* In the early game, Omniknight can look like an easy target for Spirit Breaker, but with Purification and Hammer of Purity, what could be an opportunity could quickly turn into disaster.
* Repel can be used to counter Charge of Darkness by minimizing the damage and lowering the stun duration with status resistance.
* Spirit Breaker's Greater Bash from all sources (Charge of Darkness or normal attacks) will deal no damage at all if Omniknight and his allies are protected with presence.
* Due to this, Spirit Breaker's damage will always be lower when targeting Omniknight.

* 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.

* If Medusa activates Stone Gaze before Spirit Breaker reaches her with Charge of Darkness, the charge will inevitably fail.
* Medusa has three ways to counter Spirit Breaker's Charge of Darkness: Stone Gaze can disable Spirit Breaker's Charge of Darkness if he faces Medusa directly. Aghanim's Scepter upgraded Mystic Snake can disable Spirit Breaker and cancel his Charge of Darkness if it hits him. And Cold Blooded provided by Aghanim's Shard that can cast a single-targeted Mystic Snake at Spirit Breaker if he uses Charge of Darkness on her.
* Mana Shield and overall tankiness allows Medusa to easily survive Spirit Breaker's initiation. And to make things worse, Spirit Breaker is not a common Diffusal Blade nor Disperser wielder to counter this problem at all.
* Overall, any attempt for Spirit Breaker to gank and kill Medusa will hurt him more than the other way around.

* Mana Shield makes Medusa very hard to take down in Duels.
* Stone Gaze stops Legion Commander from Dueling altogether, regardless of who she targets.

* Pit of Malice can be cast in the path of Spirit Breaker's Charge of Darkness to cancel it.
* Spirit Breaker's damage output is entirely physical, therefore Atrophy Aura is very hazardous for him in most of the stages, particularly since it also affects Greater Bash, hindering Spirit Breaker's main source of damage.
* Fiend's Gate provides a way to escape from a gank for Underlord and his teammates. Likewise, Fiend's Gate can be used to ambush Spirit Breaker who has little to no ways of intercepting Underlord and his teammates when they use it to move around the map.
Additional:
* Pit of Malice can be cast in the path of Spirit Breaker's Charge of Darkness to cancel it.
* Spirit Breaker's damage output is entirely physical, therefore Atrophy Aura is very hazardous for him in most of the stages, particularly since it also affects Greater Bash, hindering Spirit Breaker's main source of damage.
* Fiend's Gate provides a way to escape from a gank for Underlord and his teammates. Likewise, Fiend's Gate can be used to ambush Spirit Breaker who has little to no ways of intercepting Underlord and his teammates when they use it to move around the map.

* 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.

* Clockwerk can use Power Cogs to repel Spirit Breaker when he charges in with Charge of Darkness.
* Spirit Breaker's slow 0.6 second attack animation attacks do little damage against Clockwerk. It can also constantly be interrupted by Battery Assault.
* Nether Strike's 1.2 second charge time gives Clockwerk plenty of time to activate Blade Mail and for Battery Assault to cancel it.
Additional:
* Battery Assault will continuously prevent Spirit Breaker from using Nether Strike, Charge of Darkness and even right clicking because of his slow base attack speed.

* 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.

* Solar Guardian can save an ally getting targeted and focused by Spirit Breaker.

* Solar Guardian can save allies who are being dueled and will interrupt her Duel initiation.

* Astral Imprisonment can be used to protect allies by imprisoning either them or Spirit Breaker.
* Arcane Orb will heavily drain Spirit Breaker's maximum mana, rendering him almost useless and unable to cast spells. And considering how Spirit Breaker's intelligence is very low, Sanity's Eclipse will deal a lot of damage to him.
* Even if Spirit Breaker survives Sanity's Eclipse, mana allergy applied by the Sanity's Eclipse will discourage Spirit Breaker from using his abilities as it will cause him to lose health and heal Outworld Destroyer.

* 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.

* Fissure interrupts Spirit Breaker during Charge of Darkness.

* Earthshaker's AoE stuns can save ally against Duel, forcing Legion Commander to spend Aghanim's Scepter or Black King Bar.

* Nether Strike can't remove Static Link and reduces Spirit Breaker's physical damage output.
* Eye of the Storm melts Spirit Breaker's armor, and makes him much less tanky.
Additional:
* Plasma Field can slow Spirit Breaker and reduce damage from Greater Bash.
* Static Link drains damage bonus from Greater Bash, and it cannot be removed by Nether Strike.
* Storm Surge will proc on Spirit Breaker every time he attacks Razor or if he uses Charge of Darkness on Razor, damaging him and alerting Razor to Spirit Breaker's incoming ganks, no matter how far Spirit Breaker is from Razor.
* Eye of the Storm can rapidly reduce Spirit Breaker's armor, making him much less durable, especially in teamfights.

* 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.

* Nature's Grasp severely slows down Spirit Breaker, reducing effects of Charge of Darkness and Greater Bash.
* Living Armor can mitigate a large portion of Spirit Breaker's damage since his attacks are slow.
* Treant Protector can also counter-initiate against Spirit Breaker with Leech Seed, Overgrowth and with his root from Aghanim's Shard upgraded Nature's Guise before he manages to escape.
* Aghanim's Scepter gives Treant Protector access to Eyes In The Forest ability, which allows him to turn trees into wards that provide vision, allowing him to keep his allies warned about Spirit Breaker's attempts to gank them. Eyes In The Forest will also trigger Overgrowth if Spirit Breaker is in range of the tree affected by it.
Additional:
* Spirit Breaker's slow attacks cannot harm a hero shielded by Living Armor.

* 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

* Heroes with summons and illusions as Spirit Breaker has no strong AoE capabilities to deal with them: Chaos Knight, Phantom Lancer, Terrorblade, Naga Siren, Broodmother, Warlock, Visage, Nature's Prophet, Shadow Shaman, Lycan, Wraith King.

* 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.

* Malefice prevents Spirit Breaker from using his spells for the duration.
* Eidolons from Demonic Summoning have high magic resistance, receiving little damage from Charge of Darkness and Greater Bash.
* Midnight Pulse can deal big damage to Spirit Breaker, as it deals damage based on enemy hero's max health.
* Black Hole makes it very dangerous for Spirit Breaker to reach Enigma with Charge of Darkness unless if he has Nether Strike available to use.
Additional:
* Malefice prevents Spirit Breaker from using his spells for the duration.
* Eidolons from Demonic Summoning have high magic resistance, receiving little damage from Charge of Darkness and Greater Bash.
* Midnight Pulse can deal big damage to Spirit Breaker, as it deals damage based on enemy hero's max health.
* Black Hole makes it very dangerous for Spirit Breaker to reach Enigma with Charge of Darkness unless if he has Nether Strike available to use.

* 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.

* Due to Spirit Breaker's low attack speed, Supernova is problematic for Spirit Breaker to take down, and even more so with Fire Spirits debuff applied.

* 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.

* Heroes that can slow Charge of Darkness by a huge amount: Venomancer, Viper, Dazzle, Arc Warden, Lion, Huskar, Shadow Shaman, Visage, Undying, Jakiro.

* 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.

* If Luna chooses to use Eclipse in anticipation right before Spirit Breaker gets to her with Charge of Darkness, she will be able to kill Spirit Breaker before he will be able to kill her as Spirit Breaker's attack speed is rather low.
* Meanwhile, when Spirit Breaker is focusing on any of Luna's allies with Charge of Darkness, Aghanim's Scepter upgraded Eclipse can be used to counter-initate against Spirit Breaker.
* Aghanim's Shard upgraded Moon Glaives allows Luna to reduce damage from Greater Bash and Nether Strike inflicts on her, and damage Spirit Breaker whenever he is close to her, even while he is invisible.
* Lucent Beam can be used to cancel Spirit Breaker's Charge of Darkness under the condition that Luna is able to cast it on time. Lucent Beam can also be used to cancel Nether Strike. But bear in mind, however, that Spirit Breaker can counter this with Planar Pocket from Aghanim's Shard which can be used to reflect Lucent Beam back at Luna.
* If Luna buys Linken's Sphere, it will become nearly impossible for Spirit Breaker to reach Luna unless some of Spirit Breaker's allies can pop it and put it on a cooldown.
* Even though Spirit Breaker can evade all of Luna's abilities with Shadow Blade, smart Luna will always buy Dust of Appearance to provide vision on Spirit Breaker to her and her team. Luna can also buy Gleipnir to counter Spirit Breaker's Charge of Darkness and Shadow Blade combo.
Additional:
* If Luna chooses to use Eclipse in anticipation right before Spirit Breaker gets to her with Charge of Darkness, she will be able to kill Spirit Breaker before he will be able to kill her as Spirit Breaker's attack speed is rather low.
* Meanwhile, when Spirit Breaker is focusing on any of Luna's allies with Charge of Darkness, Aghanim's Scepter upgraded Eclipse can be used to counter-initate against Spirit Breaker.
* Aghanim's Shard upgraded Moon Glaives allows Luna to reduce damage from Greater Bash and Nether Strike inflicts on her, and damage Spirit Breaker whenever he is close to her, even while he is invisible.
* Lucent Beam can be used to cancel Spirit Breaker's Charge of Darkness under the condition that Luna is able to cast it on time. Lucent Beam can also be used to cancel Nether Strike. But bear in mind, however, that Spirit Breaker can counter this with Planar Pocket from Aghanim's Shard which can be used to reflect Lucent Beam back at Luna.
* If Luna buys Linken's Sphere, it will become nearly impossible for Spirit Breaker to reach Luna unless some of Spirit Breaker's allies can pop it and put it on a cooldown.
* Even though Spirit Breaker can evade all of Luna's abilities with Shadow Blade, smart Luna will always buy Dust of Appearance to provide vision on Spirit Breaker to her and her team. Luna can also buy Gleipnir to counter Spirit Breaker's Charge of Darkness and Shadow Blade combo.

* 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.

* Earthbind's root prevents/interrupts Charge of Darkness.
* As a single-target focused hero without much damage output, Spirit Breaker is ineffective in general against Meepo.

* 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.

* Ice Wall can slow down Charge of Darkness in its tracks at max level, allowing counterplays such as Cold Snap to end the charge, bursting down with Tornado, Meteor, and right clicks, or even teleporting back to spawn to drag Spirit Breaker into the fountain.
* Cold Snap (if timed right) and Invoker's other disables like Tornado can interrupt Charge of Darkness, especially since Charge is telegraphed by the symbol appearing over head.
Additional:
* Cold Snap allows Invoker to interrupt Charge of Darkness and Nether Strike.
* Tornado's long range can be used to cancel Charge of Darkness.
* Deafening Blast prevents Spirit Breaker from right clicking and thus proccing his Greater Bash.

* Invoker's spells will disable and destroy Legion Commander while she's locked in a Duel.

* Heroes with summons and illusions as Spirit Breaker has no strong AoE capabilities to deal with them: Chaos Knight, Phantom Lancer, Terrorblade, Naga Siren, Broodmother, Warlock, Visage, Nature's Prophet, Shadow Shaman, Lycan, Wraith King.

* 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".

* Heroes with ways to protect themselves or allies from Spirit Breaker's initiation: Shadow Demon, Outworld Destroyer, Omniknight, Dawnbreaker.

* 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.

* 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.

* 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.

* Heroes that can slow Charge of Darkness by a huge amount: Venomancer, Viper, Dazzle, Arc Warden, Lion, Huskar, Shadow Shaman, Visage, Undying, Jakiro.

* Magnetic Field prevents Legion Commander from getting wins with Duel.
Additional:
* Magnetic Field prevents Legion Commander from easily gaining wins with Duel.

* 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

* Heroes that can cancel Charge of Darkness: Ogre Magi, Earthshaker, Lion, Rubick, Lina, Luna, Jakiro, Dawnbreaker, Alchemist, Ogre Magi, Axe, Shadow Shaman, Naga Siren, Mars, Bane, Pudge, Clockwerk.

* 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.

* Due to Spirit Breaker's low attack speed, Tombstone is problematic for Spirit Breaker as the zombies summoned from Tombstone apply a stacking movement speed slow, which can significantly reduce Greater Bash's damage.
* Soul Rip and Decay allows Undying and his allies to survive and recover from any incoming ganks by Spirit Breaker.

* Bramble Maze stops Charge of Darkness in its tracks. Its very long duration means it can be used as an obstacle to block off an incoming Spirit Break during teamfights.
* Shadow Realm and Bedlam can be activated when Dark Willow sees Charge of Darkness coming, preventing Spirit Breaker from using Nether Strike after the initial stun.

* Mystic Flare can easily burst down Legion Commander while she is Dueling.

* 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.

* 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

* 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.

* Searing Chains can stop Charge of Darkness if timed correctly.
* Activate Fire Remnant can be used to escape an approaching Spirit Breaker, or lead Spirit Breaker into a bad situation.
* Fire Remnant and Sleight of Fist allows Ember Spirit to dodge Charge of Darkness if timed correctly.

* Spirit Breaker's slow attack speed and moderate damage do very little to harm Dragon Knight, even if ganked with Charge of Darkness.

* Durable heroes: Axe, Dawnbreaker, Bristleback, Mars, Omniknight, Tidehunter, Wraith King, Primal Beast, Underlord.

* 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.

* 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.

* Morph allows Morphling to copy abilities of Spirit Breaker and combine them with Waveform to turn things around. Aghanim's Scepter upgraded Morph also allows Morphling to create a strong illusion of Spirit Breaker that can cast all of his basic abilities. This allows Morphling to give Spirit Breaker a taste of his own medicine.
* Spirit Breaker's low attack speed and lack of burst damage makes it unlikely for him to win against Morphling when he has Attribute Shift (Strength Gain) toggled on.

* Heroes that have a weak laning stage: Spectre, Nyx Assassin, Clockwerk, Spirit Breaker, Omniknight, Pudge.

* Heroes that punish mobile heroes: Bloodseeker, Keeper of the Light, Kunkka, Disruptor.

* Heroes with gap-closing abilities who attempt to use them for escaping Bloodseeker will suffer serious damage from Rupture: Phantom Assassin, Anti-Mage, Faceless Void, Riki, Slark, Spirit Breaker.

* Heroes that can cancel Charge of Darkness: Ogre Magi, Earthshaker, Lion, Rubick, Lina, Luna, Jakiro, Dawnbreaker, Alchemist, Ogre Magi, Axe, Shadow Shaman, Naga Siren, Mars, Bane, Pudge, Clockwerk.

* Heroes that usually build Linken's Sphere as either a core or situational item: Weaver, Medusa, Morphling, Queen of Pain, Storm Spirit, Luna, Naga Siren.

* Heroes that punish mobile heroes: Bloodseeker, Keeper of the Light, Kunkka, Disruptor.

* Durable heroes: Axe, Dawnbreaker, Bristleback, Mars, Omniknight, Tidehunter, Wraith King, Primal Beast, Underlord.

* Mana Drain has an fair long range and low cooldown. It can easily deplete most heroes of their entire mana pools, especially those with smaller mana pools such as Tiny or Spirit Breaker.

* Heroes with long or multiple disables will prevent Legion Commander from winning Duels: Shadow Shaman, Lion

* Heroes who can continue dealing damage even while being stunned: Luna, Razor, Axe, Bristleback, Leshrac, Death Prophet, Jakiro.

* Heroes that can slow Charge of Darkness by a huge amount: Venomancer, Viper, Dazzle, Arc Warden, Lion, Huskar, Shadow Shaman, Visage, Undying, Jakiro.

* Heroes who rely on burst damage with magical damage will struggle to kill Primal Beast: Spirit Breaker, Gyrocopter, Leshrac

* Heroes with blink or movement abilities, which are disabled by Pounce's leash: Anti-Mage, Earth Spirit, Faceless Void, Magnus, Mirana, Monkey King, Morphling, Pangolier, Phantom Assassin, Phoenix, Puck, Queen of Pain, Riki, Sand King, Spirit Breaker, Timbersaw, Tusk.

* Heroes who rely on armor or evasion to survive can easily be bursted down, like Phantom Assassin, Terrorblade, Underlord, Spirit Breaker.

* Troll Warlord's melee bash and high attack speed can often help him and his allies win Duels against 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.

* 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

* 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.

* Can easily interrupt and disable Spirit Breaker with hex if being charged.

* Heroes with long or multiple disables will prevent Legion Commander from winning Duels: Shadow Shaman, Lion

* Heroes with summons and illusions as Spirit Breaker has no strong AoE capabilities to deal with them: Chaos Knight, Phantom Lancer, Terrorblade, Naga Siren, Broodmother, Warlock, Visage, Nature's Prophet, Shadow Shaman, Lycan, Wraith King.

* Song of the Siren lasts long enough to prevent a successful Duel (but only if Naga wasn't the target).

* Rubick can cancel Spirit Breaker's Charge of Darkness with Telekinesis under the condition that Rubick is able to cast it on time. And considering Rubick commonly buys Eul's Scepter of Divinity that can also cancel Charge of Darkness, Spirit Breaker will have a hard time charging Rubick or his allies until Spirit Breaker buys Shadow Blade. Telekinesis can also be used to cancel Nether Strike and Aghanim's Shard upgraded Telekinesis also allows Rubick to save his allies from Spirit Breaker.
* Fade Bolt weakens Spirit Breaker's damage output, reducing damage of Greater Bash.
* If Rubick succeeds to steal Charge of Darkness, he will be able to reduce much of Spirit Breaker's global presence. Rubick can also steal Nether Strike to further disable Spirit Breaker once he disables him with stolen Charge of Darkness. But bear in mind, however, that a skilled Spirit Breaker can use Bulldoze to prevent all that.

* Spirit Breaker won’t do much harm to Enchantress because of Untouchable and Nature's Attendants. Unless Enchantress is low on HP, Spirit Breaker won’t be able to catch her with mere spells.

* Heroes that punish mobile heroes: Bloodseeker, Keeper of the Light, Kunkka, Disruptor.

* 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

* Heroes that usually build Linken's Sphere as either a core or situational item: Weaver, Medusa, Morphling, Queen of Pain, Storm Spirit, Luna, Naga Siren.

* 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

* Heroes with summons and illusions as Spirit Breaker has no strong AoE capabilities to deal with them: Chaos Knight, Phantom Lancer, Terrorblade, Naga Siren, Broodmother, Warlock, Visage, Nature's Prophet, Shadow Shaman, Lycan, Wraith King.

* Heroes who can continue dealing damage even while being stunned: Luna, Razor, Axe, Bristleback, Leshrac, Death Prophet, Jakiro.

* Heroes that usually build Linken's Sphere as either a core or situational item: Weaver, Medusa, Morphling, Queen of Pain, Storm Spirit, Luna, Naga Siren.

* 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

* Heroes with summons and illusions as Spirit Breaker has no strong AoE capabilities to deal with them: Chaos Knight, Phantom Lancer, Terrorblade, Naga Siren, Broodmother, Warlock, Visage, Nature's Prophet, Shadow Shaman, Lycan, Wraith King.

* Tethered heroes are much harder for Legion Commander to kill in Duels.
* Relocate can cancel Duels and save allies.

* With Aghanim's Scepter, Broodmother will gain access to Spinner's Snare, which will allow her to create invisible lines on her webs from Spin Web that will root, deal damage over time, and reveal enemy heroes if they unwittingly step on them. This allows Broodmother to keep her allies alerted on heroes who rely on invisibility-themed and movement-themed abilities and items to surprise enemy heroes and disrupt ganking attempts of enemy heroes: Phantom Assassin, Nyx Assassin, Mirana, Bounty Hunter, Templar Assassin, Riki, Spirit Breaker, Anti-Mage, Tusk, Ursa, Nature's Prophet, Enigma, Void Spirit, Magnus etc.

* 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.

* Heroes with summons and illusions as Spirit Breaker has no strong AoE capabilities to deal with them: Chaos Knight, Phantom Lancer, Terrorblade, Naga Siren, Broodmother, Warlock, Visage, Nature's Prophet, Shadow Shaman, Lycan, Wraith King.

* Heroes that can slow Charge of Darkness by a huge amount: Venomancer, Viper, Dazzle, Arc Warden, Lion, Huskar, Shadow Shaman, Visage, Undying, Jakiro.

* Heroes with summons and illusions as Spirit Breaker has no strong AoE capabilities to deal with them: Chaos Knight, Phantom Lancer, Terrorblade, Naga Siren, Broodmother, Warlock, Visage, Nature's Prophet, Shadow Shaman, Lycan, Wraith King.

* Heroes with summons and illusions as Spirit Breaker has no strong AoE capabilities to deal with them: Chaos Knight, Phantom Lancer, Terrorblade, Naga Siren, Broodmother, Warlock, Visage, Nature's Prophet, Shadow Shaman, Lycan, Wraith King.

* 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

* Heroes with mobility spells like Queen of Pain, Anti-Mage, Phantom Assassin, Riki, Puck, and Spirit Breaker that are cancelled by Frostbite can suffer greatly from the presence of Crystal Maiden. It is absolutely critical, however, to have followup from teammates, as all of the above heroes can make quick work of the squishy Crystal Maiden after they are released from her grip.

* Heroes that can cancel Charge of Darkness: Ogre Magi, Earthshaker, Lion, Rubick, Lina, Luna, Jakiro, Dawnbreaker, Alchemist, Ogre Magi, Axe, Shadow Shaman, Naga Siren, Mars, Bane, Pudge, Clockwerk.

* Heroes who can continue dealing damage even while being stunned: Luna, Razor, Axe, Bristleback, Leshrac, Death Prophet, Jakiro.

* Heroes that can slow Charge of Darkness by a huge amount: Venomancer, Viper, Dazzle, Arc Warden, Lion, Huskar, Shadow Shaman, Visage, Undying, Jakiro.

* 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.

* Heroes with summons and illusions as Spirit Breaker has no strong AoE capabilities to deal with them: Chaos Knight, Phantom Lancer, Terrorblade, Naga Siren, Broodmother, Warlock, Visage, Nature's Prophet, Shadow Shaman, Lycan, Wraith King.

* Heroes that can slow Charge of Darkness by a huge amount: Venomancer, Viper, Dazzle, Arc Warden, Lion, Huskar, Shadow Shaman, Visage, Undying, Jakiro.

* 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

* Heroes who can continue dealing damage even while being stunned: Luna, Razor, Axe, Bristleback, Leshrac, Death Prophet, Jakiro.

* 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

* Heroes that can cancel Charge of Darkness: Ogre Magi, Earthshaker, Lion, Rubick, Lina, Luna, Jakiro, Dawnbreaker, Alchemist, Ogre Magi, Axe, Shadow Shaman, Naga Siren, Mars, Bane, Pudge, Clockwerk.