Shadow Shaman
* With all 5 Meepos available, all of Shaman's wards will be disposed of very quickly.
* All of Shaman's disables are based around single target control, and he can at most only disable two Meepos, allowing the rest to easily lay waste to him, be it during the channel duration of 
Shackles or by using 
Earthbind.
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.
Shadow Shaman
* By simply using Aphotic Shield, Abaddon can easily save his allies from heroes that apply long disables, such as 
Lion or 
Shadow Shaman.
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.
Shadow Shaman
* 
Omniknight can dispel Hex or Shackles with 
Heavenly Grace. He can also heal teammates who you disabled. The same goes for 
Abaddon's Aphotic Shield.
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.
Shadow Shaman
* 
Reincarnation allows Wraith King to survive Shadow Shaman's initial chain of disables and Serpent Ward attacks.
* Short cooldown of 
Wraithfire Blast is ideal for interrupting Shackles.
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".
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.
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
* 
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.
Shadow Shaman
* 
Arc Warden with his Magnetic Field will protect allies from Mass Serpent Ward.
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
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.
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
Legion Commander
* Solar Guardian can save allies who are being dueled and will interrupt her Duel initiation.
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.
Legion Commander
* 
Mystic Flare can easily burst down Legion Commander while she is Dueling.
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
* Earthshaker's AoE stuns can save ally against Duel, forcing Legion Commander to spend Aghanim's Scepter or 
Black King Bar.
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
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.
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.
Shadow Shaman
* Dragon Knight can simply tank and destroy all Shadow Shaman's Serpent Wards.
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.
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.
Shadow Shaman
* 
Waveform allows Morphling to escape from Mass Serpent Ward
* Morphling can interrupt Shadow Shaman while he is shackling an ally with 
Adaptive Strike (Strength).
* With 
Ethereal Blade Morphling can quickly burst him down before he even has a chance to react.
Shadow Shaman
* Mirana can disturb Shadow Shaman's channeling even if he is under the effect of invisibility thanks to 
Sacred Arrow.
* Mirana armed with an Aghanim's Scepter is known to be able to quickly burst down heroes - especially supports. Together with Ethereal Blade the bullying towards Shadow Shaman can continue for the whole match.
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.
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.
Shadow Shaman
* Luna's high magical damage burst from 
Lucent Beam and 
Eclipse can take advantage of Shadow Shaman's low health and strength gain.
* Without Black King Bar, Luna's Lucent Beam and 0.25 Eclipse Mini-stun talent for Eclipse can be used to disable Shadow Shaman while he is channeling Shackles.
* Aghanim's Scepter upgraded Eclipse combined with 0.25 Eclipse Mini-stun can repetively stun Shadow Shaman, and can even discourage him from even trying to use Shackles.
* Luna is a natural Black King Bar wielder, and almost none of Shadow Shaman's spells can bypass spell immunity, except for 
Mass Serpent Ward.
* Bear in mind, however, that if Shadow Shaman gets a jump on Luna first, he will be able to use 
Hex to disable Luna and burst her down before she can use Black King Bar, Lucent Beam or Eclipse. In addition, 
Moon Glaives cannot bounce on Mass Serpent Wards at all.
Additional:
* Luna's high magical damage burst from Lucent Beam and Eclipse can take advantage of Shadow Shaman's low health and strength gain.
* Without Black King Bar, Luna's Lucent Beam and 0.25 Eclipse Mini-stun talent for Eclipse can be used to disable Shadow Shaman while he is channeling Shackles.
* Aghanim's Scepter upgraded Eclipse combined with 0.25 Eclipse Mini-stun can repetitively stun Shadow Shaman, and can even discourage him from even trying to use Shackles.
* Luna is a natural Black King Bar wielder, and almost none of Shadow Shaman's spells can bypass spell immunity, except for Mass Serpent Ward.
* Bear in mind, however, that if Shadow Shaman gets a jump on Luna first, he will be able to use Hex to disable Luna and burst her down before she can use Black King Bar, Lucent Beam or Eclipse. In addition, Moon Glaives cannot bounce on Mass Serpent Wards at all.
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.
Shadow Shaman
* A couple of nukers and disablers on the same lane can finish a squishy Luna efficiently despite a teammate's assistance: 
Sven + Shadow Shaman.
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
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.
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.
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
Shadow Shaman
* Riki is known for being a successful support killer, something Shadow Shaman is very vulnerable to.
* 
Smoke Screen is particularly devastating to Shadow Shaman. With neither his various disables nor a solid health pool Shadow Shaman is usually dead. This forces Shadow Shaman to buy a 
Force Staff if he finds himself in this scenario and buy 
Sentry Wards if you have the money.
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
* 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.
Shadow Shaman
* Lone Druid's early game is good against slow, squishy supports since his bear is very strong early game and an Entangling Claws proc almost always guarantees a kill: Ancient Apparition, 
Crystal Maiden, Shadow Shaman, etc.
Shadow Shaman
* Heroes with channeling spells are very easy targets for Jakiro's abilities: Crystal Maiden, 
Dawnbreaker, Enigma, Pudge, 
Shadow Fiend, Shadow Shaman, Warlock.
Shadow Shaman
* 
Nyx Assassin, 
Bounty Hunter and 
Slark can all sneak up and kill Shadow Shaman, Nyx being particularly deadly. Shadow Shaman must watch out for Slark carefully, as he can break either (but not both unless he makes a mistake) of Shadow Shaman's disables, with 
Dark Pact and leap out of a serpent ward ring. These heroes, however, rely heavily on escape and are themselves not very durable and none of them can survive a full lockdown with Mass Serpent Ward. Having Sentry Wards can turn Shadow Shaman from prey to predator.
Shadow Shaman
* Heroes with summons and illusions can find themselves easily bested by Lina, like 
Broodmother, Nature's Prophet, Chen, 
Terrorblade, 
Naga Siren, 
Visage, Wraith King, Lycan, 
Phantom Lancer, Shadow Shaman.
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
* 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
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.
Legion Commander
* Song of the Siren lasts long enough to prevent a successful Duel (but only if Naga wasn't the target).
Legion Commander
* Heroes who rely on illusions will see them destroyed easily by Overwhelming Odds: Phantom Lancer, 
Chaos Knight, Terrorblade, Naga Siren
Shadow Shaman
* 
Ether Shock is a great farming ability as a handy short-cooldown nuke.
* Hex and Shackles gives Rubick extra lockdown potential in ganks and teamfights.
* Mass Serpent Ward, should Rubick steal, serves as a powerful source for teamfighting, pushing, and acquring Roshan.
* 
Arcane Supremacy allows Rubick to cast Hex and Shackles at a further distance, which keeps Rubick at a safer position compared to Shadow Shaman.
* Rubick can interrupt Shackles by casting 
Telekinesis.
Additional:
* All abilities from Shadow Shaman can very vulnearble steal from 
Spell Steal.
* Rubick can interrupt Shackles by casting Telekinesis.
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
* 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.
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
* 
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.
Shadow Shaman
* Sven is very vulnerable to chain stun such as Lion, Shadow Shaman or 
Magnus.
Shadow Shaman
* Shackles prevents Chen from acting, and damages him while healing Shadow Shaman, also allowing Shadow Shaman's allies to kill him faster. 
Aghanim's Shard upgraded Shackles can also summon four more Mass Serpent Wards to attack Chen while he is disabled. And to make things worse, Chen has no way to cancel Shackles on his own, and must rely on outside from {U:Centaur Conqueror} or {U:Mud Golem} under his control.
* Ether Shock and Mass Serpent Ward can often not only kill Chen's allies before he can save them with 
Hand of God, but they can also be used to destroy Chen's creeps easily thanks to their high damage and area-of-effect.
* Hex will prevent Chen from any attempt to save himself or his allies with Hand of God.
Additional:
* Shackles prevents Chen from acting, and damages him while healing Shadow Shaman, also allowing Shadow Shaman's allies to kill him faster. Aghanim's Shard upgraded Shackles can also summon four more Mass Serpent Wards to attack Chen while he is disabled. And to make things worse, Chen has no way to cancel Shackles on his own, and must rely on {U:Centaur Conqueror} or {U:Mud Golem} creeps under his control to be able to do so.
* Ether Shock and Mass Serpent Ward can often not only kill Chen's allies before he can save them with Hand of God, but they can also be used to destroy Chen's creeps easily thanks to their high damage and area-of-effect.
* Hex will prevent Chen from any attempt to save himself or his allies with Hand of God.
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.
Shadow Shaman
* All of Shadow Shaman's abilities totally ruin Terrorblade: Ether Shock destroys his illusions, Hex prevents him from using 
Sunder or 
Manta Style in bad situations, Shackles not only that prevent him from using Sunder, but he has no way to cancel it and Mass Serpent Ward can help Shadow Shaman push faster than Terrorblade even in 
Metamorphosis.
Additional:
* Ether Shock, Mass Serpent Wards summoned from both, Mass Serpent Ward and Aghanim's Shard upgraded Shackles can do great damage to both, Terrorblade and his illusions.
* Hex prevents Terrorblade from using Sunder or Manta Style in bad situations. Hex can also destroy one of his illusions.
* Shackles can damage Terrorblade and prevent him from using his abilities and items, whether to fight, survive, or dispel it in any way while also healing Shadow Shaman in process. In addition, Terrorblade has no solutions to cancel it. Aghanim's Shard upgraded Shackles can also summon four more Mass Serpent Wards to attack Terrorblade while he is disabled.
Legion Commander
* Duel's long duration prevents Terrorblade from swapping his health with Sunder.
* Overwhelming Odds deals high damage to Terrorblade's illusions.
Shadow Shaman
* Shadow Shaman's many disables can lock down Weaver. Even with Linken's Sphere, Weaver might not be able to escape should Shadow Shaman uses Shackles quickly enough following Hex.
* Mass Serpent Wards can make short work of Weaver once he is locked down.
Legion Commander
* Duel's long duration prevents Weaver from activating 
Time Lapse or escaping with 
Shukuchi.
Shadow Shaman
* Shadow Shaman has many disables to lock down Queen of Pain, preventing her from Blinking away, even through Linken's Sphere or her spell block talent.
* Mass Serpent Ward can tear through Queen of Pain's low health pool once she's locked down by Hex & Shackles.
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.
Shadow Shaman
* Viper cannot interrupt heroes with powerful channeling abilities: Bane, Enigma, Shadow Shaman, Warlock
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.
Shadow Shaman
* Mass Serpent Ward rips apart Huskar quickly due to his poor armor.
* As soon as Huskar jumps in, he will be vulnerable to Shadow Shaman's disables if he does not have Black King Bar.
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
* Press the Attack dispels Flaming Lasso.
* Batrider is unlikely to win a Duel in any stage of the game.
Shadow Shaman
* Shackles and Hex can both be used on Muerta while in 
Pierce the Veil, potentially wasting it until she gets Black King Bar.
* Ether Shock and Shackles can deal high damage to Muerta while she is affected by Pierce the Veil.
* However, Mass Serpent Ward cannot hurt Muerta while Pierce the Veil is active.
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
Shadow Shaman
* Shadow Shaman's Mass Serpent Ward together with Ether Shock can easily kill lots of Treants if played defensively.
* Hex and Shackles can disrupt Nature's Prophet's escape attempts with Teleportation.
Additional:
* Mass Serpent Ward can kill lots of treants if played defensively.
* Mass Serpent Ward, Hex, and Shackles can catch and kill a Nature's Prophet trying to use Teleportation.
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.
Shadow Shaman
* Shackles and Mass Serpent Ward instantly destroy 
Refraction
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.
Shadow Shaman
* As a caster, 
Anti-Mage's 
Mana Break and 
Mana Void are highly effective against him.
Shadow Shaman
* Heroes with abilities or items that can silence or disable Anti-Mage for long periods of time will prevent him from Blinking away: Lion, 
Silencer, Shadow Shaman, 
Grimstroke, 
Witch Doctor, Riki, Faceless Void, 
Skywrath Mage, 
Puck.
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.
Shadow Shaman
* Hex greatly reduces Timbersaw's mobility.
* The stun and damage over time from Shackles mitigates Reactive Armor's HP and armor regen.
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.
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.
Legion Commander
* Press The Attack dispels the stun from Shackleshot.
* Duel can lock down Windranger before she can escape with Windrun.
* Legion Commander tends to go for Blade Mail, which returns the damage she takes from Focus Fire.
Shadow Shaman
* Hex's instant cast time will force Brewmaster into the awkward situation of needing some form of spell immunity or block to prevent being immediately hex upon blinking in, or wait until Shaman has used all his crowd control before entering a fight.
* Brewmaster also has no defense against Shadow Shaman lockdowns.
Legion Commander
* Duel pierces spell immunity and forces him to attack Legion Commander, making him unable to use 
Omnislash.
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.
Shadow Shaman
* Heroes with break can disable Untouchable for a while: Doom and Shadow Demon (via Aghanim's Scepter), 
Viper, Shadow Shaman with Hex Breaks talent.
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
Shadow Shaman
* Like above, supports with reliable stuns can be a massive problem and force Black King Bar in fights unideally, such as Shadow Shaman, Lion, Nyx Assassin.
Shadow Shaman
* Heroes with illusions and summons can be hard for Phantom Assassin to deal with, as she lacks any AoE abilities to deal with them without items: Broodmother, Phantom Lancer, Chaos Knight, Lycan, Naga Siren, Shadow Shaman, Visage, Nature's Prophet, Terrorblade, Warlock, Wraith King.
Shadow Shaman
* In general, squishy heroes that rely on escape often struggle against the amount of disables Shadow Shaman can bring. 
Queen of Pain, Anti-Mage and 
Storm Spirit are among these.
Shadow Shaman
* Any hero who can counter-initiate in anticipation without getting caught in Reverse Polarity: Sven, Omniknight, Enigma, 
Luna, Naga Siren, 
Mars, 
Jakiro, 
Venomancer, 
Elder Titan, Faceless Void, Rubick, Keeper of the Light, 
Pugna, Invoker, 
Spectre, 
Alchemist, Treant Protector, 
Lina, Oracle, Zeus, Shadow Shaman, Phoenix, 
Razor, 
Huskar, 
Batrider, 
Kunkka, 
Tidehunter, Wraith King, 
Sand King, 
Medusa, Dawnbreaker.
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.
Shadow Shaman
* Heroes with channeling spells because Shadow Fiend has nothing to cancel channeling outside of Requiem of Souls: Bane, Enigma, Pudge, Shadow Shaman, Dawnbreaker, Warlock, Crystal Maiden.
Legion Commander
* Heroes who rely on summons will see them destroyed easily by Overwhelming Odds: Lycan, Arc Warden, Warlock, Chen
Legion Commander
* 
Tethered heroes are much harder for Legion Commander to kill in Duels.
* 
Relocate can cancel Duels and save allies.
Shadow Shaman
* Heroes with both illusions and summons, for Io has nothing to deal with multiple enemies at once outside from Spirits's weak area-of-effect: 
Beastmaster, Broodmother, Chaos Knight, Lycan, Naga Siren, Nature's Prophet, Phantom Lancer, Shadow Shaman, Terrorblade, Visage, Warlock, Wraith King.
Legion Commander
* Duel is very effective against Io due to its low health and armor.
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
Shadow Shaman
* Heroes that can keep Marci for a long time in one place so she can't pursue her targets, like Bane, Lion, Shadow Shaman, Invoker, 
Disruptor and Kunkka.
Additional:
* Shadow Shaman can provide an excellent counter-initiation against her 
Rebound. His abilities can shut down any of her tower dive attempts in the laning phase.
* Shackles keeps Marci stunned for an extended time, wasting her ultimate. A combo with Mass Serpent Ward only makes things worse for her, as her armor is low.
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
* Heroes who rely on summons will see them destroyed easily by Overwhelming Odds: Lycan, Arc Warden, Warlock, Chen
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.
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
* Troll Warlord's melee bash and high attack speed can often help him and his allies win Duels against Legion Commander.
Shadow Shaman
* Shadow Shaman's long disables are effective at kiting and wasting the duration of Battle Trance.
* Mass Serpent Ward are especially effective against Troll Warlord during Battle Trance, as trapping him inside them during the duration is effectively another hard disable, as Troll cannot attack the wards or use Phase Boots to escape.
Shadow Shaman
* Heroes that have a channeled ability that can be interrupted by Meat Hook: Shadow Shaman, Witch Doctor, Enigma, Bane.
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.
Shadow Shaman
* Heroes that are squishy by nature are an easy target for Spirit Breaker: 
Sniper, 
Drow Ranger, Shadow Shaman
Shadow Shaman
* Can easily interrupt and disable Spirit Breaker with hex if being charged.
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.
Shadow Shaman
* With 4 active abilities, Shadow Shaman is weak against silencing foes such as Silencer, Drow Ranger and 
Death Prophet.
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.
Shadow Shaman
* Spectre's entire ability set is designed to get to and destroy heroes that stay in the backlines, both carries (like the aforementioned Drow Ranger and Sniper) and supports (like 
Dazzle and Shadow Shaman).
Shadow Shaman
* Hex can be used immediately to destroy Spectre's illusion when she 
Haunts.
* Shadow Shaman can use Shackles to lock down Spectre for his team.
* Shadow Shaman's Mass Serpent Ward and Ether Shock help him push lanes and end the game early before Spectre can come online and take over the late game.
Shadow Shaman
* With 4 active abilities, Shadow Shaman is weak against silencing foes such as Silencer, Drow Ranger and Death Prophet.
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.
Shadow Shaman
* Nyx Assassin, Bounty Hunter and Slark can all sneak up and kill Shadow Shaman, Nyx being particularly deadly. Shadow Shaman must watch out for Slark carefully, as he can break either (but not both unless he makes a mistake) of Shadow Shaman's disables, with Dark Pact and leap out of a serpent ward ring. These heroes, however, rely heavily on escape and are themselves not very durable and none of them can survive a full lockdown with Mass Serpent Ward. Having Sentry Wards can turn Shadow Shaman from prey to predator.
Legion Commander
* Duel's long duration prevents Nyx Assassin escaping from 
Vendetta. With Aghanim's Scepter, she can also bypass 
Spiked Carapace.
Shadow Shaman
* Support heroes with low mobility can be slowed further by Incapacitating Bite, and swarmed by Spiderlings for an easy kill: Shadow Shaman, Visage, Dazzle, Rubick, Lich.
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
* 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 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.
Legion Commander
* Invoker's spells will disable and destroy Legion Commander while she's locked in a Duel.
Shadow Shaman
* Heroes with long lockdowns: Shadow Shaman, Legion Commander.
Legion Commander
* Heroes with long lockdowns: Shadow Shaman, Legion Commander.
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.
Shadow Shaman
* Hex abilities can cancel the channelling of Fiend's Grip : Lion, Shadow Shaman, Dazzle from Aghanim's Shard with upgraded 
Poison Touch.
Legion Commander
* Heroes with strong dispels can dispel Bane's disables from their allies: Oracle, Legion Commander, Omniknight.
Shadow Shaman
* Sniper can easily destroy Mass Serpent Wards from long range.
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.
Shadow Shaman
* Single-target disablers will have difficulty locking down a Chaos Knight with Phantasm active: Bane, Beastmaster, 
Bloodseeker, 
Clockwerk, Doom, Shadow Shaman.
Legion Commander
* Heroes with strong area damage to destroy Phantasm illusions: Axe, 
Ember Spirit, Legion Commander, Phoenix
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.
Shadow Shaman
* 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.
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.
Shadow Shaman
* With 4 active abilities, Shadow Shaman is weak against silencing foes such as Silencer, Drow Ranger and Death Prophet.
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
* 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.
Shadow Shaman
* Heroes who can clear the waves of Enigma's Eidolons: Lina, Luna, Dawnbreaker, Jakiro, Shadow Shaman, Death Prophet, Keeper of the Light, Invoker, 
Leshrac, Puck.
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
Shadow Shaman
* Heroes with silence and mana drain abilites, as Ancient Apparition relies entirely on his abilities: Invoker, Silencer, Nyx Assassin, Skywrath Mage, Shadow Shaman, Lion and etc.
Shadow Shaman
* Nyx Assassin, Bounty Hunter and Slark can all sneak up and kill Shadow Shaman, Nyx being particularly deadly. Shadow Shaman must watch out for Slark carefully, as he can break either (but not both unless he makes a mistake) of Shadow Shaman's disables, with Dark Pact and leap out of a serpent ward ring. These heroes, however, rely heavily on escape and are themselves not very durable and none of them can survive a full lockdown with Mass Serpent Ward. Having Sentry Wards can turn Shadow Shaman from prey to predator.
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.
Shadow Shaman
* Due to their high attack speed,
Summon Familiars will destroy Mass Serpent Wards quickly, granting Visage a massive amount of gold.
Stone Form of the Familiars to cancel Shackles. 
Aghanim's Shard upgraded 
Stone Form also allows Visage to use 
Stone Form himself to cancel Shackles while restoring his health.
Grave Chill can make Shadow Shaman's bad movement speed and attack speed even worse.
Bloodthorn wielder, which allows him to silence Shadow Shaman and make him more vulnerable to damage.
Mass Serpent Ward quickly, granting Visage massive amount of gold.
* Visage can use
*
* Visage is also a natural
Additional:
* Due to their high attack speed, Visage's Summon Familiars will destroy
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.