* Enchantress often has a small army of neutral creeps, allowing Medusa to hit her with a later bounce of her Mystic Snake.

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

* Amazingly, Enchantress has even lower health than Pugna. Though she does pack quite a punch through Impetus, she can't use it if she is under Decrepify.
* Pugna's Magical DPS is way greater than the heal from Nature's Attendants, which will also harm her quite a bit if she's next to Nether Ward.

* 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

* Heroes with nukes that can jump her: Clockwerk, Snapfire, Spirit Breaker, Techies

* 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.

* Heroes with nukes: Bane, Lich, Lion, Skywrath Mage

Additional:
* Untouchable is useless versus constant Arcane Bolts, and it doesn't help that her strength gain is the lowest in the game.
* A jungle Enchantress can weaken lanes and make Skywrath Mage's job easier.
* The magic amplification from Ancient Seal makes her even squishier to Skywrath and his allies' magic nukes.

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

* Battle Trance and Fervor can help Troll Warlord deal with Enchantress through Untouchable.
Additional:
* Untouchable's attack speed slow is easily remedied by Fervor stacks and Battle Trance.
* Troll Warlord is a natural Silver Edge carrier, disabling Enchantress' Untouchable.

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

* Enchantress has a very low health pool, allowing Zeus to burst her down quickly before she can heal off the damage with Nature's Attendants.
* 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 damage from Impetus.
* The exception is the laning phase, where Enchantress can gank Zeus if she Enchants a good creep.
Additional:
* 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.

* 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

* Magnetic Field makes Impetus miss; if Enchantress decides to enter the field, she is giving up bonus damage since Impetus deals greater damage at higher distance away from targets.

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

* Meepo can quickly kill Enchantress with a Poof combo, rendering Untouchable useless.

* 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.

* Heroes with break can disable Untouchable for a while: Doom and Shadow Demon (via Aghanim's Scepter), Viper, Shadow Shaman with Hex Breaks talent.

* 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.

* Heroes with little health or magic resistance are easily picked off with Oracle's magic burst, such as Skywrath Mage, Crystal Maiden, or Enchantress.

* 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.

* 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.

* 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.

* 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.

* 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.

* Heroes with nukes: Bane, Lich, Lion, Skywrath Mage

* 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.

* Enchantress has a very small health pool and cannot tank Lina's heavy magic burst.
* Untouchable is decently countered by Fiery Soul, exposing Enchantress's weakness to physical damage due to her low armor.
* Lina is decent at clearing creeps and can kill Enchantress's creeps quickly.
Additional:
* Enchantress has pitiful health, and cannot tank Lina's heavy magic damage.
* Untouchable is decently countered by Fiery Soul, exposing Enchantress's weakness to physical damage due to her low armor.
* Lina is decent at clearing creeps and can kill Enchantress' creeps quickly.

* Untouchable doesn't work against Unleash, as Marci gains 1000+ attack speed for the fury combo.
* Enchantress' low health makes her a fragile target for Marci's damage blasts.
* Marci can use Rebound on one of her enchanted creeps to easily reach the Enchantress and negate the bonus damage dealt by her Impetus. It helps that most of her best creeps have a low attack range, creating a makeshift bridge towards their master.

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

* 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.

* 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.

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

* 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.

* 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.

* 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.

* Enchantress has pitiful HP, even more pitiful than Luna, so Lucent Beam and Eclipse will often harass and/or kill her through her Untouchable.
* With Moon Glaives, Luna can clear Enchantress's creep wave efficiently.
Additional:
* Though Enchantress's Untouchable can greatly reduce Luna's attack speed, and can go through any form of Spell Immunity, she has a pitiful HP so Lucent Beam and Eclipse can kill her very quickly.
* Moon Glaives allows Luna to clear Enchantress's creeps very efficiently.

* 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.

* All of Tinker's damage is magic/pure and completely ignores Enchantress's Untouchable. And Tinker's nukes can quickly decimate her small HP pool, sometimes even preventing Enchantress from even responding.
* As Enchantress relies solely on her primary attacks to deal damage, and rarely builds something to dispel it, Laser's Blind is particularly effective.
* However, Enchantress will probably build a Linken's Sphere against Tinker's Laser, so getting an additional disable is highly recommended.

* 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 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

* 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 break can disable Untouchable for a while: Doom and Shadow Demon (via Aghanim's Scepter), Viper, Shadow Shaman with Hex Breaks talent.

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

* Heroes with haste can negate Enchant's slow: Weaver, Dark Seer, Lycan, Centaur Warrunner.

* 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.

* Sand King is a strong ganker, allowing him to shut down squishy heroes in the early game: Phantom Assassin, Clinkz, Sniper, Enchantress.

* Heroes with haste can negate Enchant's slow: Weaver, Dark Seer, Lycan, Centaur Warrunner.

* 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 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.

* Riki usually buys Diffusal Blade to initiate, which renders Enchantress' movement speed useless, and is usually followed with Smoke Screen.
* Riki can effectively hit Enchantress by Tricks of the Trade alongside with Diffusal Blade and Smoke Screen's initiation. For a hero like Enchantress, 3 to 4 hits from Riki is a big deal, unless Enchantress built Force Staff earlier.

* 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 can jump on her: Slark, Queen of Pain, Anti-Mage

* Heroes with nukes: Bane, Lich, Lion, Skywrath Mage

Additional:
* Enchantress is very fragile without any form of magic resistance, allowing Lion to easily burst her down.
* Nature's Attendants is a slow heal, making not as much effective against Lion's burst as it could be.
* Her raw movement speed is a fair escape/mobility mechanism, which may allow her to avoid a blindly cast Earth Spike, but does nothing against the rest of Lion's abilities, since they are single target and can't miss.
* Since Lion's damage comes mostly from his skills, Untouchable does nothing to mitigate it.

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

* 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.

* Doom with the {ValueColor:1|Doom applies Break|25tal} {Symbol:Talent} talent can be useful against heroes with troublesome passive skills while also disabling them for a long time: Phantom Assassin, Enchantress, Huskar, Underlord.

Additional:
* Devour can easily eat creeps controlled by Enchant, limiting her ganking potential.
* Doom reduces the amount of healing received by Enchantress and her allies from Nature's Attendants. In addition, when Doom chooses the Doom applies Break talent, it can also disable Untouchable.

* Heroes with nukes that can jump her: Clockwerk, Snapfire, Spirit Breaker, Techies

* Enchant can not control golem Chaotic Offering from Warlock.

* The burst damage from Timbersaw's abilities is more than enough to deal with Enchantress and her creeps.
* Timbersaw doesn't rely on his physical attacks, which makes Untouchable useless against him.
* Timber Chain can close the gap between them and minimize damage from Impetus.
* Bear in mind, however, that Timber Chain can also work against Timbersaw if used to escape and that Impetus can ignore Reactive Armor if Enchantress is not a primary target for Timbersaw or if he is disabled.
* Timbersaw is a common wielder of Lotus Orb, which will allow him to reflect Enchant back at Enchantress and dispel most debuffs as well.

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

* 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.

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

* Untouchable won't mitigate Venomancer's magical damage, and Enchantress is vulnerable to magic damage.
* Both Venomous Gale and Poison Nova lower the amount of healing received by Enchantress and her allies from Nature's Attendants.

* Heroes with haste can negate Enchant's slow: Weaver, Dark Seer, Lycan, Centaur Warrunner.

* 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

* Heroes like Enchantress and Chen, or heroes that make use of Helm of the Dominator are weak to Crystal Maiden, as Frostbite can do wonders against Enchant, Holy Persuasion, or dominated creeps. Careful though, as an army of carefully controlled creeps (Enchantress and Chen) can hold many stuns that will cancel Freezing Field.

Additional:
* Frostbite does 1000 magical damage to Enchantress's creeps and roots them for 10 seconds, which hinders her ability to gank.

* Heroes that can jump on her: Slark, Queen of Pain, Anti-Mage

* 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 can jump on her: Slark, Queen of Pain, Anti-Mage

Additional:
* Queen of Pain often relies more on abilities than right-clicks, making Untouchable nearly useless against her.
* Enchantress also has a lower health pool than Queen of Pain, making her vulnerable to Queen of Pain's damage burst.

* Heroes with nukes that can jump her: Clockwerk, Snapfire, Spirit Breaker, Techies

* Heroes with haste can negate Enchant's slow: Weaver, Dark Seer, Lycan, Centaur Warrunner.

* Heroes with break can disable Untouchable for a while: Doom and Shadow Demon (via Aghanim's Scepter), Viper, Shadow Shaman with Hex Breaks talent.

* Heroes with nukes that can jump her: Clockwerk, Snapfire, Spirit Breaker, Techies

Additional:
* Techies does huge amounts of magical damage, which will bypass Untouchable.
* Enchantress depends on abilities to do damage and heal, which Blast Off's silence prevents.

* Mirana can instantly kill creeps with Sacred Arrow, making her decent at crippling the armies of Chen or Enchantress.

* 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 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

* Vendetta can deal great damage against her. However, it requires an direct attack, so Nyx Assassin may have difficulties applying Vendetta on her.
* Enchantress's lack of mobility makes her a primary target for ganking with Vendetta.
* Mind Flare can deal a great damage against her due to being an Intelligence hero.
* Spiked Carapace can reflect Impetus and stun Enchantress.
Additional:
* Spiked Carapace reflects the damage from Impetus.
* Enchantress is a rather squishy hero, making her fall easily to Nyx Assassin's high burst damage.

* Blade Fury dispels the slow from Enchant, and can burst Enchantress down during the laning stage.
* Omnislash and Swiftslash's physical damage burst ignore untouchable.
* Silver Edge is a common item for Juggernaut for dealing with Untouchable.
Additional:
* Blade Fury dispels the slow from Enchant, spell immunity and used to burst her down during the early laning stage.
* Omnislash and Swiftslash's physical damage burst ignore Untouchable.
* Silver Edge is an ideal item for Juggernaut to deal with Untouchable, making her vulnerable to melee attacks.

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

* Windrun's speed allows easy pursuit or escape, while the evasion greatly reduces the threat of Enchantress's Impetus, especially when retreating.
* Shackleshot is a powerful disable if Enchantress gets too close to one of her own minions.
* Focus Fire can negate Untouchable.

* Heroes with nukes: Bane, Lich, Lion, Skywrath Mage

* Enchantress's lack of area-of-effect abilities allows Broodmother to swarm her with Spiderlings.
* Spawn Spiderlings can kill enchanted creeps and create Spiderlings in their place.
* However, bear in mind that Untouchable makes it harder for Broodmother to actually hit Enchantress, even if Broodmother is spell immune. And Broodmother's only way to counter this is either by buying Silver Edge, buying items that deal high magical damage like Dagon, or by buying items that give high attack speed like Moon Shard.
Additional:
* Enchantress can be easily overwhelmed with Broodmother's spiderlings from Spawn Spiderlings and Enchantress can only control one of them with Enchant and she has no good waveclear (Spawn Spiderlings can also kill creeps controlled with Enchant).
* However, Untouchable's attack speed reduction can make it difficult for Broodmother to kill Enchantress even with any form of spell immunity.

* 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.

* 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

* 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.