Zeus
* Even though Pugna's low HP means that he can be quickly burst down, his 
Nether Ward heavily punishes casters whose spells cost a lot of mana, like Zeus. Casting 4 of his active spells, including Nimbus, close to an enhanced level 4 Nether Ward, can make the ward deal up to 1750 magical damage.
* 
Decrepify can further increase the damage dealt by Nether Ward upon Zeus. However, if used on Pugna himself or on one of his allies, it will amplify the damage done by Zeus' abilities.
Legion Commander
* Decrepify on either hero stops Legion Commander from completing a Duel, and dissuades her from initiating Duels on ethereal allies.
* 
Life Drain can help Pugna's teammates win a fight, either by killing Legion Commander or replenishing her target's health.
Additional:
* Decrepify prevents Legion Commander from attacking allies during 
Duel, regardless if it's used on her or on the ally .
* Pugna can easily cast Decrepify, Nether Blast and Life Drain on Legion during the 4/4.75/5.5/8 seconds of duel
Zeus
* 
Enrage will make it very difficult to burst him down.
* Zeus has little armor, HP and mobility; Ursa's favorite kind of target.
Legion Commander
* 
Fury Swipes can give Ursa the edge in Duels.
* Enrage's instant cast time allows it to be used before Legion Commander initiates a Duel, causing Ursa to take almost no damage for a brief period of time.
* However, Duel stops Ursa from casting Enrage at the most critical moment
Zeus
* Visage can quickly kill heroes with low to medium base armor and no innate escape mechanism. Examples include 
Alchemist, 
Crystal Maiden and 
Zeus.
Legion Commander
* 
Gravekeeper's Cloak protects Visage from Legion Commander's attacks for most of Duel's duration.
* Chain stuns from Visage's familiars prevents Legion Commander from winning Duels.
Zeus
* Heroes with long range abilities are also able to touch Zeus, such as 
Clockwerk, 
Kunkka, 
Puck, 
Skywrath Mage, 
Spirit Breaker, 
Tusk and others.
Legion Commander
* 
Mystic Flare can easily burst down Legion Commander while she is Dueling.
Zeus
* Heroes with long range abilities are also able to touch Zeus, such as Clockwerk, Kunkka, Puck, Skywrath Mage, Spirit Breaker, Tusk and others.
Legion Commander
* Battery Assault's mini-stuns can severely disrupt Legion Commander's attack animation when she enters a Duel, potentially saving Clockwerk (or his allies) and possibly even giving him an edge in securing a win himself.
* Power Cogs pushes Legion Commander away from Clockwerk's allies when she enters a Duel.
Zeus
* Heroes with a lot of burst damage, especially those who rely on casting spells: 
Lina, Zeus.
Legion Commander
* 
Mana Shield makes Medusa very hard to take down in Duels.
* 
Stone Gaze stops Legion Commander from Dueling altogether, regardless of who she targets.
Zeus
* Heroes who cannot prevent Sven from killing supports will always be at a disadvantage in fights such as Lina, 
Slark and Zeus.
Legion Commander
* 
God's Strength makes Sven one of the worst heroes to Duel.
* 
Storm Hammer can be used to interrupt Duels.
* 
Warcry gives a big boost in passive defensive ability with the active component to nearby allies.
* With the Aghanim Shard Warcry also gives nearby allies passive increases.
Zeus
* Heroes with long range abilities are also able to touch Zeus, such as Clockwerk, Kunkka, Puck, Skywrath Mage, Spirit Breaker, Tusk and others.
Legion Commander
* Heroes who can hide the Dueled target (
Outworld Destroyer, 
Shadow Demon, Tusk, 
Phoenix with 
Aghanim's Scepter etc).
Additional:
* Walrus PUNCH! makes Legion Commander lose Duel easily, especially when she doesn't have 
Blade Mail. Tusk can also snowball dueled allies, preventing them from taking damage for a large portion of the duel's duration.
Legion Commander
* If he isn't broken (break), Abaddon can use Borrowed Time to waste Legion Commander's Duel, As Borrowed Time has a shorter cooldown, Legion Commander can't win duels, effectively reducing her targets by one, Duel also means that Borrowed Time heals Abaddon for the duration of the duel, as Legion can't stop attacking.
Additional:
* 
Aphotic Shield and 
Mist Coil makes it hard for Legion Commander to kill Abaddon's teammates in Duels.
* 
Borrowed Time makes Abaddon nearly impossible to kill in Duels, and often replenishes much of his health because Legion Commander cannot manually stop attacking during Duels.
Legion Commander
* 
Paralyzing Cask can save ally from Legion Commander Duel's until she purchases Aghanim's Scepter.
* 
Voodoo Restoration can heal Witch Doctor allies from Duel's.
* 
Death Ward can help Witch Doctor allies from winning Duel's, if, he is not a target.
Legion Commander
* 
Astral Imprisonment prevents Legion Commander from killing her opponents in Duels.
Additional:
* Outworld Destroyer can save an ally hero caught by Duel with Astral Imprisonment, and he can inflict heavy damage on Legion Commander with Arcane Orb to aid his ally. However, if he gets caught, he is unlikely to survive the duel, due to his lack of durability.
Zeus
* Heroes that depend on disrupting fights with ability combos or big ultimate abilities are vulnerable to the long stun of Fiend's Grip: 
Disruptor, 
Death Prophet, 
Enigma, 
Faceless Void, 
Invoker, 
Lich, 
Magnus, 
Mars, 
Medusa, Outworld Destroyer, Phoenix, Puck, 
Queen of Pain, 
Shadow Fiend, 
Treant Protector, 
Underlord, 
Winter Wyvern, 
Witch Doctor, Zeus.
Legion Commander
* Bane has powerful single-target abilities that can help his allies win Duels, or at least cripple Legion Commander for the duration.
* Nightmare can waste Duel's entire duration as the dueled units transfer the Nightmare back and forth. This may be prevented if a non-Dueling unit attacks the Nightmared Dueler.
Additional:
* 
Enfeeble, 
Nightmare and 
Fiend's Grip all prevent Legion Commander from winning Duels, especially when Bane has 
Blink Dagger.
Legion Commander
* Heroes with strong dispels can dispel Bane's disables from their allies: 
Oracle, 
Legion Commander, 
Omniknight.
Legion Commander
* 
Purification prevents Legion Commander from killing her target, and will always hit her during Duels.
* 
Guardian Angel completely wastes Duel's duration and can save an ally across the map when upgraded with Aghanim's Scepter.
Additional:
* Both Guardian Angel and Purification are perfect counters against Duel.
Zeus
* Marci on the midlane will win the laning phase against Zeus almost every time, as her powerspike at level 6 will decimate Zeus' low health pool and force him to stay far back.
* Even before level 6, Dispose and Sidekick can easily take half of Zeus' health if he is in range of Dispose.
Zeus
* 
Time Dilation can limit Zeus to casting his abilities only once in a fight, effectively serving as a 6/8/10/12 second silence.
* 
Time Walk negates Zeus's burst damage.
* 
Chronosphere makes Zeus the best target for Void because of his low mobility.
Legion Commander
* Solar Guardian can save allies who are being dueled and will interrupt her Duel initiation.
Legion Commander
* 
Atrophy Aura's percentage-based damage reduction greatly diminishes Legion Commander's overall damage output, even if she has won many Duels
* Legion Commander cannot get out the way of Firestorm because she is stationary.
Additional:
* Atrophy Aura makes it hard for Legion Commander to win Duels.
* 
Fiend's Gate can be used to save Underlord and his allies from a Duel or to intercept Legion Commander, because outside from 
Overwhelming Odds, Legion Commander has no other area-of-effect abilities.
Legion Commander
* 
Static Link drains Legion Commander's accumulated damage, effectively neutralizing her overall primary advantage, and prevents her from winning Duels.
* 
Storm Surge's movement speed buff makes Razor and his allies harder to catch and initiate.
* 
Eye of the Storm, if used beforehand, will always hit Legion Commander during Duels, due to her forced proximity. This drastically lowers her survivability during Duel.
Zeus
* Zeus laneing against Ember is going to be punished with Sleight of Fist due to his low health pool
* Zeus's chip damage from 
Arc Lightning and other spells is nullified from Ember's Flame Guard.
Additional:
* Ember Spirit has a built-in antimagic shield, and Zeus has nothing but this magical damage, because of this, their confrontation on the center line can turn out to be sad for Zeus. If on such a line Ember Spirit will finish off all creeps under its 
Flame Guard, and Zeus with the help of Arc Lightning, then eventually Zeus will lose mana faster, and will be forced to look for ways to replenish it
* Ember Spirit can interrupt Zeus with his "jumping" abilities, the fact is that Zeus deals damage from his abilities directly, while Ember Spirit disappears for milliseconds from the battlefield when flying during the 
Sleight of Fist action or when flying into 
Fire Remnant
Legion Commander
* 
Lucky Shot can disarm Legion Commander and reduce her armor, which can reduce her chances of winning a duel. If an ally is targeted, Pangolier can simply use 
Swashbuckle to inflict it on her.
* If an enemy Pangolier casts a well-timed 
Rolling Thunder before Legion Commander can cast Duel, it might result in her chasing down Pangolier until his or her ultimate ends, whichever duration ends first, resulting in an open window for enemy allies to target Legion Commander, making her vulnerable and susceptible to any source of attacks. If Legion Commander has an Aghanim's Scepter in her inventory, the risk of wasting a solid 8 seconds would result in a futile duel.
* Dueling Pangolier is normally a mistake, Pangolier can disarm you in the duel, and potentially gain some Duel damage, Only duel Pangolier if at least 1 ally is nearby, and he is on low health, And even then, be wary, A good duel can easily turn against you with one Lucky Shot (Due to Lucky Shot lasting 4 seconds).
Additional:
* Swashbuckle can be used to disarm Legion Commander while she is Dueling an ally, granting her opponent a considerable advantage, Lucky Shot lasts 4 seconds at most wasting Legion Commander's entire Duel, (Or half, if Legion Commander has the Scepter).
* Legion Commander will try not to duel Pangolier alone, as she will almost inevitably lose, thanks to Lucky Shot's disarm, If Legion Commander wants to duel a Pangolier, she must be with atleast a teammate, and if she has her scepter, 3 or 4 teammates.
* Legion Commander is often with her allies, allowing you to rack up some considerable damage resistance with Shield Crash.
Legion Commander
* Heroes with global abilities can give Legion Commander's opponent an edge in Duels from anywhere on the map: 
Nature's Prophet, 
Ancient Apparition, Zeus, Invoker, Treant Protector
Zeus
* Heroes with long range abilities are also able to touch Zeus, such as Clockwerk, Kunkka, Puck, Skywrath Mage, Spirit Breaker, Tusk and others.
Legion Commander
* 
Wraith King's 
Reincarnation allows him to severely punish Legion Commander after he revives, as her abilities are on cooldown. Legion Commander is still awarded a Duel win if Wraith King reincarnates.
Additional:
* Wraith King makes a poor Duel target, as he can be already quite hard to bring down once, and then you have to worry about his second life.
* However, even if Legion Commander does win the duel when Reincarnation is off cooldown, she still receives the permanent victory damage bonus because taking down Wraith King's first life still counts as a "kill".
Zeus
* Heroes with low mobility that rely on spells: Zeus, Lina, Crystal Maiden.
Legion Commander
* Heroes with global abilities can give Legion Commander's opponent an edge in Duels from anywhere on the map: Nature's Prophet, Ancient Apparition, Zeus, Invoker, Treant Protector
Zeus
* Heroes who have most or all their abilities (damage or disable) unable to pierce spell immunity: 
Keeper of the Light, Lina, 
Lion, Zeus.
Additional:
* 
Rage is very useful against Zeus, as it negates magic damage and provides spell immunity. In addition, the increased attack speed can tear Zeus apart in combination with 
Open Wounds.
* Lifestealer can avoid Thundergod's Wrath with 
Infest.
Zeus
* Heroes with long range abilities are also able to touch Zeus, such as Clockwerk, Kunkka, Puck, Skywrath Mage, Spirit Breaker, Tusk and others.
Legion Commander
* Heroes who can hide the Dueled target (Outworld Destroyer, Shadow Demon, Tusk, Phoenix with Aghanim's Scepter etc).
Additional:
* Legion Commander relies on her powerful attack and her Duel to be effective. But if Phoenix gets the jump on her first, she can find herself severely slowed, taking heavy damage, and find herself unable to Duel a burning Supernova.
* It must be noted that 
Press the Attack will both dispel the attack slow of Fire Spirits and grant her or whoever she targets bonus attack speed. This allows her to easily destroy a Supernova if caution is not taken to prevent this from occurring. As such, it would be a better decision to simply avoid a farmed or skilled Legion Commander instead of attempting to overpower her.
* If an ally is caught by Duel, Phoenix can use Sun Ray to heal the ally and damage Legion Commander, possibly swinging the Duel in their team's favor. Or with Aghanim's Scepter, Phoenix can save an ally from dying in Duel with Supernova and cancel the Duel as well.
Zeus
* As a spellcaster, silences will nullify him entirely. Some notable examples are Death Prophet, 
Drow Ranger, 
Bloodseeker, Disruptor and many others.
* 
Doom, as usual, fits this description nicely.
Legion Commander
* Heroes who can hide the Dueled target (Outworld Destroyer, Shadow Demon, Tusk, Phoenix with Aghanim's Scepter etc).
Additional:
* Disruption can save allies and mess up an initiation from an enemy Legion Commander. Using Disruption on your ally that is affected by Duel will leave her totally exposed without the benefit of the life steal from 
Moment of Courage. A precise decision to Disrupt Legion Commander or her victim is crucial to waste Duel's potential.
* Demonic Purge cannot be dispelled by a hard dispel from Press the Attack, which in turn can be dispelled by your ultimate.
Zeus
* As a spellcaster, silences will nullify him entirely. Some notable examples are Death Prophet, Drow Ranger, Bloodseeker, Disruptor and many others.
* Doom, as usual, fits this description nicely.
Zeus
* Heroes with long range abilities are also able to touch Zeus, such as Clockwerk, Kunkka, Puck, Skywrath Mage, Spirit Breaker, Tusk and others.
Zeus
* Zeus can deal a huge amount of damage, but he lacks defensive abilities, such as good mobility or resistance. Due to that, he doesn't like to be touched by any means. Heroes with higher damage output and good mobility will often get easily near Zeus and trade damage (eventually causing Zeus's downfall). Such Heroes include: 
Lycan, Slark, 
Storm Spirit, 
Spectre and others.
Zeus
* Heroes with summons that are destroyed by a fixed number of attacks: 
Undying's 
Tombstone, 
Gyrocopter's 
Homing Missile, and Zeus's 
Nimbus.
Legion Commander
* Magnetic Field prevents Legion Commander from getting wins with Duel.
Additional:
* 
Magnetic Field prevents Legion Commander from easily gaining wins with Duel.
Legion Commander
* Heroes who rely on summons will see them destroyed easily by Overwhelming Odds: Lycan, 
Arc Warden, 
Warlock, 
Chen
Zeus
* Chaos Knight's high health pool makes him resistant to Zeus' burst damage. 
Phantasm can dispel 
Veil of Discord, a typical item purchased by Zeus.
* Zeus is easily overwhelmed by Chaos Knight's strong illusions, as Arc Lightning is not enough to kill them fast enough to have any impact.
* Zeus' low base armor makes him extremely vulnerable to Chaos Knight's high damage output and armor reduction.
Legion Commander
* Heroes with strong area damage to destroy Phantasm illusions: 
Axe, 
Ember Spirit, Legion Commander, Phoenix
Legion Commander
* 
Fate's Edict prevents Legion Commander from attacking for a few seconds, potentially saving Oracle's ally.
* 
Fortune's End dispels Press the Attack's healing and attack speed buff, as well as the movement speed bonus from Overwhelming Odds.
* 
False Promise protects allies and prevents Legion Commander from winning Duels and gaining bonus damage.
Additional:
* Provided that the enemy team does not have an Axe, Oracle can guarantee that his ally survives for the duration of the Duel with False Promise and has decent nuke potential to help ally to win a Duel. He can also disarm Legion Commander with Fate's Edict.
* Oracle can dispel enemy buffs like Overwhelming Odds and Press the Attack with Fortune's End.
Legion Commander
* Heroes with long disables, like Lion, 
Night Stalker, or Legion Commander, can prevent Oracle from using spells or items.
Zeus
* Zeus burst damage can be reduced by 
Dispersion and reflect some of the damage back to Zeus himself.
* Zeus has low mobility and stays in backlines, 
Spectral Dagger or 
Haunt can easily catch him as he has no escape mechanism.
* Since Zeus has low HP, Spectral Dagger and 
Desolate will quickly tear Zeus down when he's alone.
Zeus
* Zeus is good against heroes that juke in trees or up cliffs, like 
Batrider, 
Monkey King, Spectre, and 
Tinker, by providing vision in any area with Lightning Bolt, or guaranteeing vision on enemies with Thundergod's Wrath.
Zeus
* Huskar's Burning Spears chip through his low health pool quickly.Consequently, he is forced to either invest on health regen or abandon the lane.
* Reliant on magic damage, there is little he can do against Huskar.
* Huskar will usually kill him if he gets Life Break off,given Zeus' poor mobility.
Legion Commander
* Carries that can out damage Huskar will do well against him: Legion Commander, Faceless Void, 
Troll Warlord, 
Phantom Assassin.
Additional:
* 
Life Break is almost suicidal when used on Legion Commander, as it invites an instant Duel and Legion Commander herself is a natural Blade Mail carrier.
* Huskar's low survivability and mostly on low health make him particularly vulnerable to Legion Commander's high physical damage.
Legion Commander
* 
Cold Embrace saves allies from dying in Duels.
* 
Winter's Curse turns Legion Commander's high damage against her allies, giving the enemy team little time to react.
* However, Winter Wyvern lanes very poorly against Legion Commander due to Press the Attack removing all the debuffs she can give. Winter Wyvern also has little chances of surviving if she gets Dueled herself.
Additional:
* Cold Embrace is very effective against Duel.
* Also, casting Winter's Curse at Legion Commander while an ally is in a Duel will stun her for most of the duration, possibly preventing lethal damage dealt to your ally. It can also turn her high-damage against her teammate.
Zeus
* Heavy nukers will do well against Cold Embrace (Lina, Zeus etc).
Additional:
* Any ally that Winter Wyvern tries to save with Cold Embrace can still be damaged by all of Zeus's spells.
* If Winter Wyvern tries to juke vision by flying up a cliff or in the trees, Zeus can gain vision there with Lightning Bolt or Thundergod's Wrath.
* If Zeus is forced to attack an ally by Winter's Curse, his unimpressive attack damage and attack speed means they won't be hurt much by him. Zeus will also stay near the back of fights away from his allies, making a deadly Curse less likely.
Zeus
* Zeus' main source of damage is his low cooldown, high damage spells - meaning Last Word and Global Silence will pretty much take him out of the game for the duration.
* Zeus likes to spam his abilities, which makes him vulnerable to Arcane Curse.
* If Zeus dies near Silencer, he will begin to lose intelligence, reducing his mana pool, mana regen, and attack damage. Furthermore, if the game is long and Zeus dies often, the intelligence losses will also reduce his spell damage.
Additional:
* Silencer's 
Global Silence will render Zeus useless for 6 seconds in a team fight.
* 
Arcane Curse will punish Zeus for casting spells, which can cause continuous damage to him should he continue to cast spells.
* 
Last Word can silence Zeus and prevent him from spamming his spells.
* Silencer often builds 
Orchid Malevolence (or 
Bloodthorn) which can be used on spell casters like Zeus, forcing him to invest in a 
Linken's Sphere.
Legion Commander
* Heroes that can disable or silence Silencer for a long time, such as 
Bane and Legion Commander, can lock down Silencer while their allies put him down.
Legion Commander
* 
Shallow Grave prevents Legion Commander from killing her opponents in Duels.
* 
Shadow Wave will heal an ally caught in a Duel, as well as dealing damage to Legion Commander.
Zeus
* Some heroes with extreme range, like Zeus, Invoker or Clockwerk, can snipe your allies from anywhere after your Grave has expired.
Zeus
* Although 
Lightning Bolt and 
Thundergod's Wrath can reveal Templar Assassin during Meld, Zeus nonetheless has no way to deal with Refraction.
* Zeus is a rather squishy hero, falling easily to Templar Assassin's high burst damage.
Additional:
* 
Refraction blocks all of Zeus' damage and Zeus has no innate way of removing the instances quickly.
* 
Meld helps burst down Zeus' small health pool while he's still working through the Refraction instances.
* 
Psi Blades allow her to harass and zone Zeus in lane.
* Templar Assassin usually buys Blink Dagger, enabling her to quickly close the gap to Zeus' defensive positioning.
Zeus
* Heroes who can provide True Sight are always credible threats: 
Slardar, 
Bounty Hunter, especially Zeus since his Lightning Bolt provides True Sight without the need to detect her beforehand to apply the debuff. So even a late-coming Zeus can easily scout a large area to reveal her, and she cannot purge herself from his sight with the dispel talent.
Zeus
* Arc Lightning and Lightning Bolt can easily burst Terrorblade and his illusions.
* 
Static Field from 
Aghanim's Shard can automatically hit everything in a big radius, taking a huge chunk of health out of Terrorblade's illusions, regardless of how much health they have.
Legion Commander
* Duel's long duration prevents Terrorblade from swapping his health with 
Sunder.
* Overwhelming Odds deals high damage to Terrorblade's illusions.
Zeus
* Arc Lightning has a low cooldown can used to pop his Linken's Sphere.
* Lightning Bolt or (Nimbus upgraded from Aghanim's Scepter) detects Weaver during Shukuchi, preventing his ganks.
* Thundergod's Wrath can kill Weaver quickly before he can cast his Time Lapse at low health.
Legion Commander
* Duel's long duration prevents Weaver from activating 
Time Lapse or escaping with 
Shukuchi.
Zeus
* Zeus can reveal Clinkz with Lightning Bolt.
* He is vulnerable to Zeus's magical nukes, due to his low health pool.
Legion Commander
* 
Searing Arrows and Clinkz physical damage items are almost suicidal when used on Legion Commander, as it invites an instant Duel and Legion Commander herself is a natural Blade Mail carrier.
* Duel locks down Clinkz for a long duration, preventing him from escaping with 
Skeleton Walk.
Zeus
* Zeus is good against heroes that juke in trees or up cliffs, like Batrider, Monkey King, Spectre, and Tinker, by providing vision in any area with Lightning Bolt, or guaranteeing vision on enemies with Thundergod's Wrath.
Legion Commander
* Press the Attack dispels Flaming Lasso.
* Batrider is unlikely to win a Duel in any stage of the game.
Zeus
* Since Windranger is bad against magical damage, heroes with continuous magical damage or magical nukes can blast her: Zeus, Tinker, 
Leshrac, 
Viper, Skywrath Mage, Lion, Lina, 
Venomancer.
Legion Commander
* Press The Attack can save allies dispell from Shackleshot.
* Duel can lock before escape with Windrun.
* Focus Fire potentially trigger with Blade Mail can Windranger's useless.
Zeus
* Lich does not pose a big threat to Zeus in teamfights, as his spells don't have great cast range and Zeus should be too far back for a 
Chain Frost to bounce among him and his allies.
* Lich has a low health pool, allowing Zeus to burst him down quickly.
Legion Commander
* Heroes with low health will die easily during Duels, and can be farmed for damage in the early game: Crystal Maiden, Lich, 
Techies, 
Rubick
Zeus
* Lightning Bolt makes roaming behind enemy lines more and more difficult as Zeus becomes powerful enough to spam it. Also, Zeus' Ultimate Thundergod's Wrath reveals Bounty Hunter regardless of his position.
Additional:
* Bounty Hunter has a very low health pool, allowing Zeus to burst him down quickly.
* Zeus can cast Lightning Bolt to gain True Sight in any area he suspects Bounty Hunter may be invisible or any area he thinks Bounty Hunter may have warded.
* If Bounty Hunter tries to escape a gank by using 
Shadow Walk, Zeus can gain vision of him with both Lightning Bolt and Thundergod's Wrath.
Legion Commander
* Legion Commander with Press the Attack
* Heroes that can remove the Track debuff with their skills:
* 
Abaddon with Aphotic Shield and Borrowed Time
* 
Huskar with Life Break
* 
Juggernaut with 
Blade Fury
* Legion Commander with Press the Attack
* 
Lifestealer with Rage and Infest
* 
Naga Siren with 
Mirror Image
* Omniknight with 
Heavenly Grace
* Oracle with Fortune's End and False Promise
* 
Phantom Lancer with 
Doppelganger
* Slark with 
Dark Pact
* 
Ursa with Enrage
* 
Weaver with Time Lapse
* 
Tidehunter with 
Kraken Shell when damage received reaches the threshold.
Legion Commander
* Heroes with abilities that blind or cause Legion Commander to miss will prevent her from winning Duels: Arc Warden, Keeper of the Light, 
Riki, Tinker
Zeus
* Zeus's Lightning Bolt and Thundergod's Wrath provides a short duration of True Sight, revealing Riki while possibly dealing a heavy amount of damage.
* Zeus's Nimbus can be placed directly on top of 
Tricks of the Trade, potentially causing him to be damaged, stunned, and revealed the instant he becomes targetable again.
Legion Commander
* Another great threat to Riki since her Duel forces him to fight from the front and expose him for the entire duration, almost always guaranteeing an easy win (unless Riki has allies helping him).
* Moment of Courage can become hard to deal with as it doesn't cease with silence.
Legion Commander
* Heroes with abilities that blind or cause Legion Commander to miss will prevent her from winning Duels: Arc Warden, Keeper of the Light, Riki, Tinker
Zeus
* Zeus can easily reveal Tinker's location in the trees with Thundergod's wrath.
* When Zeus has an Aghanim's Scepter, he can use his Nimbus, together with Lightning Bolt to interrupt Tinker's 
Keen Conveyance channelling and cancel Tinker's Blink Dagger.
Additional:
* Due to Tinker's low health pool, Zeus can easily burst Tinker down, while also cancelling 
Rearm.
* Once Zeus gets Aghanim's Scepter, he will gain Nimbus, which allows him to scout out Tinker on the map, especially when he is pushing lanes while hiding in the trees.
Legion Commander
* Press the Attack can dispel Laser's blind while providing great attack speed and health regeneration.
* Once caught in a Duel, Tinker, who completely relies on his spells to be effective, has little chances of survival with his low health pool and armor.
Zeus
* Heroes with global nukes will target and hit Phantom Lancer regardless of his illusions: Zeus
Legion Commander
* Heroes who rely on illusions will see them destroyed easily by Overwhelming Odds: Phantom Lancer, 
Chaos Knight, 
Terrorblade, Naga Siren
Additional:
* Overwhelming Odds deals high damage to Phantom Lancer's illusions.
* Duel's long duration prevents Phantom Lancer from using Doppelganger.
Zeus
* Enchantress has a very low health pool, allowing Zeus to burst her down quickly before she can heal off the damage.
* Zeus will not be affected by 
Untouchable, as he won't try to attack her with right clicks anyway.
* Zeus can stay out of her attack range while trying to kill her, especially if he has bought an 
Aether Lens.
* Most heroes would want to get on top of Zeus to kill him, but Enchantress does not have this option as doing so would severely limit her 
Impetus damage.
* The exception is the laning phase, where Enchantress can gank Zeus if she Enchants a good creep.
Zeus
* Zeus deals enormous amounts of magic damage, being one of the best heroes to burst down Timbersaw early in the game.
* Lightning Bolt's mini-stun can stop Timbersaw's from escaping a fight with Timber Chain.
* Timbersaws tend to build health increasing items, making Zeus' Static Field deal huge amounts of damage.
Additional:
* 
Reactive Armor will not trigger from Zeus's spells or protect Timbersaw from their damage.
* Early game Timbersaw's strength is average and Zeus can heavily aid in bursting him down.
* Late game, if Timbersaw has built a lot of HP items, Zeus's passive Static Field will be more effective at chipping away Timbersaw's large HP pool.
* A Timbersaw who builds 
Pipe of Insight will be much more difficult to kill, as Zeus has no way to hold Timbersaw down, but Timbersaw will have less armor, mana, and damage than normal if he buys this item early game just to counter Zeus.
Legion Commander
* Duel is a great initiation to target Crystal Maiden with, as it prevents her from using Freezing Field or any other abilities and allowing the enemy team to quickly kill her before she can aid her team in a fight.
Zeus
* Zeus can easily find Magnus who is often hiding in the trees with Thundergod's Wrath and Lightning Bolt, which allows him to warn allies and disrupt his initiation attempts.
Legion Commander
* Sniper's low mobility and lack of defensive abilities make him an easy gank target for the entire game, especially if Blink Dagger is picked up.
Zeus
* Due to Hoodwink's low health and Zeus's high magic damage from Arc Lightning, Lightning Bolt and Static Field as well as global abilities from Thundergod's Wrath and Nimbus, he can easily kill her throughout the game and also reveal where Hoodwink is positioned or when she's in trees.
Zeus
* Arc Lightning allows Zeus to get farm in lane against Shadow Fiend without coming into the range of his Shadowrazes.
* Lightning Bolt can be used to heavily harass Shadow Fiend when he tries to get a last hit.
* Thundergod's Wrath and Lightning Bolt can be used to detect Shadow Fiend if he tries to escape with 
Shadow Blade.
Legion Commander
* Duels prevents Queen of Pain from using Blink, which may force her to purchase a Linken's Sphere
* Because Queen of Pain is also not a right-click hero, Legion won't have much difficulties in duels.
* Press the Attack dispels Shadow Strike's debuff.
Zeus
* Zeus's enormous magical damage output makes Pierce the Veil risky to use without a 
Black King Bar.
* Zeus does not rely on attack speed, making 
The Calling nearly pointless against him.
* If Zeus is ever too close to Muerta, he can use 
Heavenly Jump to disengage.
Legion Commander
* Duel makes Bristleback fight Legion Commander face to face, forcing him to take full damage.
* Press the Attack dispels the slow from stacks of Viscous Nasal Goo.
Additional:
* When dueled, Bristleback will have to face Legion head on, not allowing his passive 
Bristleback to come into effect.
Zeus
* Zeus usually stays at the back in teamfights and it is hard for Sand King to find Zeus and knock him down before Zeus deals his damage.
* All of Zeus' abilities, especially Thundergod's Wrath, disables Sand King's Blink Dagger, effectively reducing Sand King's initiation and counter-initiation potential.
* Lightning Bolt deals damage to Sand King in Sand Storm and reveals him. It also interrupts channeling of Epicenter.
Legion Commander
* Overwhelming Odds's damage stacks with each enemy unit in its radius. If this hits Broodmother and a large number of spiders it can deal significant amounts of damage.
* Moment of Courage has a high chance to proc if Broodmother and all of her spiders are attacking her.
* Duel can keep Broodmother in place long enough for Legion's team to kill her.
Additional:
* Overwhelming Odds is great at killing many stacked up spiderlings, thus giving Legion Commander a large buff.
* Duel is a reliable way to lock down Broodmother, preventing her from running into the treeline.
Legion Commander
* Duel's long duration prevents Nyx Assassin escaping from 
Vendetta. With Aghanim's Scepter, she can also bypass 
Spiked Carapace.
Zeus
* Necrophos' 
Ghost Shroud increases the magic damage taken by Necrophos.
* If Zeus builds both an 
Ethereal Blade and Veil of Discord, it almost always guarantees a kill.
Legion Commander
* Chen's fragility and low mobility make him an enticing Duel target.
* Overwhelming Odds and Moment of Courage can take advantage of converted creeps's numbers.
* With enough damage from Duel stacks, Legion Commander can also often kill any of Chen's unfortunate allies before he can use Hand of God.
Additional:
* Chen's frailty and low mobility make him an enticing Duel target.
* Overwhelming Odds and Moment of Courage can take advantage of converted creeps' numbers.
* With enough damage from Duel stacks, Legion Commander can also often kill any of Chen's unfortunate allies before he can use 
Hand of God.
Legion Commander
* Because Duel requires both combatants to face each other, 
Bulwark's effectiveness will be increased by a huge margin, which makes it much more difficult for Legion Commander to win any duels against him.
* 
Spear of Mars and 
God's Rebuke pushes Legion Commander away during Duels against allies.
Additional:
* Bulwark immensely mitigates Duel, even with bonus physical damage, as Bulwark scales by percentage. Mars can also buy time for a dueled ally by pushing Legion Commander away with Spear of Mars.
Zeus
* Mars' own father is a formidable foe because Zeus deals massive amounts of magical damage. The high damage, low cooldown nukes of Arc Lightning and Lightning Bolt combined with the percent health magic damage of Static Field will shred Mars' health because it bypasses Bulwark completely.
Legion Commander
* Legion Commander is both good and bad vs Mars, on the plus side she can dispel Spear of Mars with Press the Attack and is a good 
Silver Edge carrier. However, Mars is not an ideal Duel target, as Bulwark will force her to 1: Buy Silver Edge, and 2: Hit Mars with it before the Duel, allowing a skilled Mars to react, especially with 
Eul's Scepter of Divinity. In teamfights, Mars will happily draw attention after using his abilities, and tank the Duel with all spells on cooldown.
Legion Commander
* Heroes with low health will die easily during Duels, and can be farmed for damage in the early game: Crystal Maiden, Lich, Techies, Rubick
Legion Commander
* Heroes with low health will die easily during Duels, and can be farmed for damage in the early game: Crystal Maiden, Lich, Techies, Rubick
Legion Commander
* Heroes that cannot move in fights such as a Dueling Legion Commander or anyone channeling a spell like Bane, 
Pudge, or Enigma are easy Sacred Arrow targets.
Zeus
* Heroes with spells that negate invisibility such as Bounty Hunter, Zeus and Slardar prevent her from saving her allies with Moonlight Shadow.
Legion Commander
* Heroes that can protect or dispel stunned allies such as Legion Commander, Outworld Destroyer, Shadow Demon and Oracle can reduce the effectiveness of Sacred Arrow.
Legion Commander
* Heroes rely on their debuff to control the opponent will have a hard time against Press the Attack: Venomancer, 
Earth Spirit, 
Ogre Magi
Legion Commander
* Special mention to Legion Commander, as she can lock down Void Spirit for a long amount of time without worrying too much about being killed by him during the Duel.
Zeus
* Heroes with high magical burst damage will kill Gyrocopter before he gets to do much: Lina, Lion, Zeus
Legion Commander
* Long lockdown is a great way to deal with Axe to prevent Berserker's Call from being used, heroes such as Legion Commander, 
Beastmaster and 
Primal Beast are good examples of this.
Legion Commander
* Invoker's spells will disable and destroy Legion Commander while she's locked in a Duel.
Zeus
* Zeus greatly hinders Invoker on the line with his long-range abilities. QW- and QE-Invoker have a very long recharge on abilities, and Zeus' Arc Lightning ability recharges too quickly, which is why he quickly kills a pack of creeps and drives Invoker under his tower, punching and not letting finish off creeps
* Lightning Bolt and Thundergod's Wrath abilities reveal invisibility of enemies, for example Invoker invisibility from 
Ghost Walk ability
Additional:
* Zeus greatly hinders Invoker on the line with his long-range abilities. QW- and QE-Invoker have a very long recharge on abilities, and Zeus' Arc Lightning ability recharges too quickly, which is why he quickly kills a pack of creeps and drives Invoker under his tower, punching and not letting finish off creeps
* Lightning Bolt and Thundergod's Wrath abilities reveal invisibility of enemies, for example Invoker invisibility from Ghost Walk ability
Legion Commander
* Heroes with long lockdowns: 
Shadow Shaman, Legion Commander.
Legion Commander
* Heroes rely on their debuff to control the opponent will have a hard time against Press the Attack: Venomancer, Earth Spirit, Ogre Magi
Legion Commander
* A well-timed 
Eclipse before a Duel usually prevents Legion Commander from winning Duels, if Luna is the target.
* Meanwhile, when Luna is not a target, Eclipse and 
Lucent Beam can also help an ally win a Duel against Legion Commander.
* However, skilled Legion Commander will always buy a Black King Bar to block Eclipse and Lucent Beam or Aghanim's Scepter to reduce it's damage.
Additional:
* A well-timed Eclipse before a Duel usually prevents Legion Commander from winning Duels if Luna is the target. Luna can also buy Linken's Sphere to block Duel.
* Meanwhile, when Luna is not a target, Eclipse and Lucent Beam can also help an ally win a Duel against Legion Commander.
* Bear in mind, however, that skilled Legion Commander will always buy a Black King Bar to block Eclipse and Lucent Beam or Aghanim's Scepter to reduce their damage.
Zeus
* Zeus's highly damaging nuke spells with low cooldowns is not something Luna can go against, though Luna can win against Zeus in late game.
* Thundergod's Wrath can be used before a fight to harm Luna before she activates Black King Bar, reducing her survivability for that fight.
* For the same reasons, Zeus makes a very powerful ally for Luna when they are in the same team.
Legion Commander
* Heroes that can keep Luna locked down for a long time can be a threat (she is very item and spell dependent): Faceless Void, Legion Commander, 
Doom.
Legion Commander
* Heroes with global abilities can give Legion Commander's opponent an edge in Duels from anywhere on the map: Nature's Prophet, Ancient Apparition, Zeus, Invoker, Treant Protector
Zeus
* Heroes who can provide True Sight or semi-reveal enemy heroes as Nature's Prophet is prone to buying Shadow Blade: Bounty Hunter, Slardar, Spectre, Zeus, Spirit Breaker.
Legion Commander
* Legion Commander's Overwhelming Odds deals damage for every Treant it hits, which allows it to easily wipe out large waves of them.
Legion Commander
* Heroes who rely on summons will see them destroyed easily by Overwhelming Odds: Lycan, Arc Warden, Warlock, Chen
Zeus
* Heroes with powerful spammable abilities will prove problematic for Grimstroke as Ink Swell does not protect him from them: Zeus, Skywrath Mage, Tinker, Lina
Legion Commander
* Heroes rely on their debuff to control the opponent will have a hard time against Press the Attack: Venomancer, Earth Spirit, Ogre Magi
Additional:
* Press the Attack dispels Venomous Gale and Poison Sting from Legion Commander or her teammates.
* Venomancer is an ideal target for Duel due to his lack of mobility and low starting health.
Legion Commander
* Song of the Siren lasts long enough to prevent a successful Duel (but only if Naga wasn't the target).
Zeus
* Zeus's abilities deal high amounts of burst magical damage, which ignores Naga Siren's high armor.
* Arc Lightning is a good way to destroy Naga Siren's illusions due to it's capabilities to bounce between enemies.
* Static Field from Aghanim's Shard can automatically hit everything in a big radius, taking a huge chunk of health out of Naga Siren's illusions, regardless of how much health they have.
Legion Commander
* Heroes who rely on illusions will see them destroyed easily by Overwhelming Odds: Phantom Lancer, Chaos Knight, Terrorblade, Naga Siren
Legion Commander
* Enigma can be a perfect counter-initiator with his ultimate. A perfectly timed Black Hole will turn the tide of any initiation, especially from heroes like; Spirit Breaker, Legion Commander, Axe, Puck, and Slardar.
Zeus
* Zeus can break Blink Dagger with his long range abilities and global range ultimate, Thundergod's Wrath.
* Lightning Bolt has a long range and a mini-stun, providing a way for him to cancel Black Hole from safe distances, assuming Enigma doesn't have his Black King Bar.
* Zeus's Aghanim's Scepter grants him Nimbus ability that has a global range and mini-stun, making it an even more effective way to cancel Black Hole before Enigma initiates with Black King Bar.
* Zeus is typically able to position himself at a safe distance from the fight, making him a difficult target to capture in a Black Hole.
Zeus
* As a spellcaster, silences will nullify him entirely. Some notable examples are Death Prophet, Drow Ranger, Bloodseeker, Disruptor and many others.
* Doom, as usual, fits this description nicely.
Legion Commander
* Drow Ranger's low mobility and lack of defensive abilities make her an easy gank target in the early to mid-game.
* A Dueling Drow Ranger will lose her precious 
Marksmanship, reduce her damage output significantly, and will more likely lose that Duel.
Legion Commander
* Heroes with abilities that blind or cause Legion Commander to miss will prevent her from winning Duels: Arc Warden, Keeper of the Light, Riki, Tinker
Legion Commander
* Press the Attack can dispel Blinding Light or Solar Bind from a hero.
* Duel can be used to instantly take Keeper of the Light out of a team-fight.
Zeus
* Spirit Siphon does a lot of magical damage, especially in the early game. This allows her to demolish low health heroes such as Zeus, 
Pugna, especially when combined with her other spells.
Legion Commander
* Duel is a great initiation to kill Death Prophet before she can cast Exorcism. Furthermore, Legion Commander often builds Blade Mail and can reflect Exorcism's damage to kill Death Prophet easily.
Legion Commander
* Heroes with long or multiple disables will prevent Legion Commander from winning Duels: Shadow Shaman, Lion
Legion Commander
* Lion is extremely dependent on his abilities. Silences like 
Silencer's Last Word, magic resistance like Oracle's Fate's Edict, and dispels like Legion Commander's Press the Attack all make his abilities less effective.
Legion Commander
* Heroes that lack burst damage will have a difficult time taking down Monkey King, and fare badly against Jingu Mastery: Legion Commander, Lifestealer, Weaver, Wraith King
Zeus
* Zeus is good against heroes that juke in trees or up cliffs, like Batrider, Monkey King, Spectre, and Tinker, by providing vision in any area with Lightning Bolt, or guaranteeing vision on enemies with Thundergod's Wrath.
Zeus
* Zeus likes to stay far back in fights, dealing his damage uninterrupted, but once he gets hooked into the fight, he usually dies very quickly.
* Pudge's high strength from Flesh Heap makes it very hard for Zeus to burst him down.
* Zeus' low health pool makes him very vulnerable to the damage from Meat Hook, Rot and Dismember.
Additional:
* 
Meat Hook's high range allows Pudge's team to drag Zeus in the middle of the fight and abuse his frailty.
* 
Flesh Heap's health and magic resistance bonus makes Pudge exceptionally resistant to Zeus' nukes. In later stages of the game, Zeus is usually unable to seriously damage Pudge at all. Even Static Field, which deals damage based on a percentage of the enemy's health, won't be doing much.
* Even if Zeus buys a Black King Bar, Meat Hook and 
Dismember still disable him for a long time, usually causing Zeus' quick death.
* Zeus is vulnerable to early ganks, which Pudge excels at.
Legion Commander
* Legion Commander can use Press the Attack on an ally to dispel Dismember. The bonus health regeneration also partially counters the damage of Rot
* Duel can be used on Pudge whilst Rot is active, disabling toggling which may result in a lethal health drain that leaves Legion Commander with a successful duel.
Zeus
* Zeus can deal a huge amount of damage, but he lacks defensive abilities, such as good mobility or resistance. Due to that, he doesn't like to be touched by any means. Heroes with higher damage output and good mobility will often get easily near Zeus and trade damage (eventually causing Zeus's downfall). Such Heroes include: Lycan, Slark, Storm Spirit, Spectre and others.
Zeus
* Heroes with heavy magical nukes will take advantage of Slark's poor HP or force him to use Shadow Dance early: Lina, Lion, Zeus
Zeus
* None of Zeus's abilities can damage a Juggernaut in Blade Fury.
* Zeus's short attack range makes it difficult for him to target a well-placed 
Healing Ward. His frequent use of Arc Lightning will have almost no effect on allies being healed by Juggernaut.
* Zeus has no way to defend himself, even if Juggernaut cannot use Blade Fury. He can be easily taken out if cornered, sometimes even without 
Omnislash.
Additional:
* Blade Fury negates all magical damage from Zeus.
* Omnislash can easily take down Zeus. However, be aware that most players will get a Eul's Scepter of Divinity or a 
Ghost Scepter against Juggernaut.
Legion Commander
* Duel pierces spell immunity and forces him to attack Legion Commander, making him unable to use Omnislash.
Zeus
* 
Corrosive Skin severely reduces Zeus's damage output throughout the game.
* During the laning stage, Viper can abuse Zeus' reliance on spells by hugging the creep wave. Zeus will take constant damage over time from Corrosive Skin unless he drives Viper from the lane or returns to farming in his absence.
* Prior to buying Blink Dagger or 
Force Staff, Zeus is fragile and possesses low mobility. Any of Viper's numerous slows can set up an easy kill.
Additional:
* Corrosive Skin counters Zeus in lane by canceling the effects of 
Clarity as Zeus relies on Arc Lightning to farm and secure last hits.
* Corrosive Skin also increases Viper's magic resistance to shrug off Zeus's magical nukes.
* 
Nethertoxin breaks Static Field.
* Due to Zeus' poor mobility, 
Viper Strike will cripple Zeus and will allow Viper and his teammates to land a lot of attacks.
Legion Commander
* Viper's frailty and low mobility make him an enticing Duel target and Corrosive Skin doesn't protect him against Legion Commander physical attacks.
* Press the Attack can dispel 
Poison Attack.
* Viper slows can easily negate by Overwhelming Odds movement speed.
Legion Commander
* Earthshaker's AoE stuns can save ally against Duel, forcing Legion Commander to spend Aghanim's Scepter or Black King Bar.
Zeus
* Thundergod's Wrath will often disable Earthshaker's Blink Dagger before a fight starts.
Zeus
* Once you get a Black King Bar, squishy spellcasters like Zeus, Skywrath Mage and others will be probably easy to deal with.
Legion Commander
* Heroes who rely on summons will see them destroyed easily by Overwhelming Odds: Lycan, Arc Warden, Warlock, Chen
Legion Commander
* Troll Warlord's melee bash and high attack speed can often help him and his allies win Duels against Legion Commander.
Zeus
* Heroes with mediocre health pools who rely on armor or evasion to survive fights such as Troll Warlord, 
Windranger, and Terrorblade can be killed by Zeus if caught off guard.
Legion Commander
* Heroes with long or multiple disables will prevent Legion Commander from winning Duels: Shadow Shaman, Lion
Legion Commander
* Pudge, Legion Commander and Axe will make the match a living hell for Shadow Shaman, since they are known for surprise attacks from the fog and quickly killing low HP heroes. They can also interrupt Shadow Shaman's channeling, Legion being especially problematic, as she can use Press the Attack on an ally who is hexed as well.
Zeus
* Zeus almost exclusively relies on magical damage, which is heavily reduced by Counterspell.
* Zeus' complete lack of mobility makes him very easy for Anti-Mage to chase down with Blink.
* Zeus likes to stand in the back during team fights, but Anti-Mage can easily Blink to close the distance.
Additional:
* Anti-Mage can burn mana, which is a big problem for a spellcaster like Zeus that heavily relies on it.
* 
Counterspell decreases magical damage taken from Zeus.
* Zeus' high intelligence and mana pool makes him a perfect target for 
Mana Void.
Legion Commander
* Duel renders Anti-Mage's escape capabilities with Blink and Counterspell useless. Blade Mail and Moment of Courage work well against Anti-Mage's relatively low health.
* A good initiation from Legion Commander and her team is enough to effortlessly kill Anti-Mage.
Additional:
* Counterspell offer no protection against Duel at all.
* Duel locks down Anti-Mage for a long duration, preventing him from escaping with 
Blink. One successful Duel initiation is usually enough for Legion Commander's team to kill Anti-Mage.
Legion Commander
* 
Tethered heroes are much harder for Legion Commander to kill in Duels.
* 
Relocate can cancel Duels and save allies.
Legion Commander
* Duel is very effective against Io due to its low health and armor.
Legion Commander
* With armor items like 
Solar Crest or 
Assault Cuirass combined with Bash of the Deep, Slardar can easily tank the Duel, If not dueled himself, he can drop Legion Commander's armor during duel and/or buff his teammate and save them, leaving her only the choice of dueling supports which can also be saved with fast Blink into Slithereen Crush.
Zeus
* Slardar has high priority on building moblity items such as Blink Dagger rather than tank items. Zeus can easily deal large amount of damage to him if not caught out of position first.
Zeus
* Thundergod's Wrath strikes only the first Meepo.
Earthbinds are easy to hit and he'll quickly die from 
Poofs.
* Zeus has low mobilty so consecutive
Legion Commander
* When Legion Commander uses
Duel on one Meepo, he can use his other Meepos to kill her. If he wasn't dueled, he can help the teammate who was duelled to give the teammate the damage instead of Legion Commander.
* However, if Legion Commander picked up an Aghanim's Scepter and she duels one Meepo, that might be the end of Meepo if Legion managed to gather enough damage from previous duels.