Venomancer
* 
Corrosive Skin means Viper can often outlast Venomancer in a battle of attrition.
* Venomancer has no mobility without items, which makes him vulnerable to constant slows.
Mars
* 
Nethertoxin breaks the damage block from Bulwark.
* 
Poison Attack and 
Viper Strike's slows make it difficult for Mars to contribute to fights due to his low mobility.
Additional:
* Viper Strike can disable 
Bulwark entirely, making Mars far less tanky. Using Nethertoxin inside 
Arena of Blood may discourage enemies from following up with Mars's initiation.
* 
Rod of Atos is currently common on Viper and keeps Mars in position long enough to be killed.
* However, Viper is not very tanky earlier in the game, so positioning against Mars is important for Viper since a well-timed 
Spear of Mars can be the end of Viper.
Venomancer
* Snowball can be used to save allies or himself during 
Venomous Gale and 
Poison Nova.
* Venomancer lacks mobility and has low base health, so he can be killed by Walrus PUNCH!
Mars
* 
Snowball can protect Tusk and his teammates from a Spear of Mars' stun after an Arena of Blood, and with proper targeting, even bring them out of the Arena. This is especially noticeable in the earlier stages of the game before allies buy 
Black King Bar and rely on this less. Even during the late-game, Tusk can purchase a 
Blink Dagger to save allies that are caught before Black King Bars can be used by Blinking in and Snowballing out.
* 
Tag Team is a constant threat to Mars in-lane, as it deals significant damage and slow, making Bulwark slightly ineffective.
* It is worth noting that 
Ice Shards can be detrimental to Tusk's own team by creating terrain that Spear of Mars can latch on, though using it conservatively is a good enough solution in most cases.
Venomancer
* In the laning stage, making illusions of Venomancer will turn his 
Poison Sting back at him, making for an easy gank at level one, and for later when your mid comes for ganks.
Mars
* Heroes with break abilities: 
Shadow Demon (with 
Aghanim's Scepter), 
Viper.
Venomancer
* Any hero that can outrange Plague Ward can neutralize them without putting themselves at risk of receiving Poison Sting: 
Arc Warden, 
Chen, 
Clinkz, 
Drow Ranger, 
Lina, 
Mirana, 
Nature's Prophet, 
Pugna and 
Sniper.
* Special mention to heroes that outrange Plague Ward after obtaining talents that increase attack range.
Mars
* 
Nether Blast, 
Decrepify and 
Life Drain deal high magical damage and bypasses Bulwark.
* 
Nether Ward reduces the amount of abilities Mars can use during fights and forces Mars to be careful about the heavy mana cost of Arena Of Blood.
* Pugna is one of few heroes that can contest Mars' ability to push and defend towers early on.
Venomancer
* Squishy heroes or heroes without hard disables or silences: Shadow Demon, 
Shadow Fiend, 
Venomancer, 
Ancient Apparition etc.
Mars
* 
Ball Lightning makes it almost impossible to catch Storm Spirit without someone else initiating for you.
* 
Overload is not reduced by Bulwark and the magical damage spam can wear down Mars quickly.
Additional:
* Storm Spirit's abilities all do magical damage, which can bypass Bulwark.
* Ball Lightning can escape through Arena of Blood and it is easy to dodge Spear of Mars.
Venomancer
* Vulnerable spellcasters with no escape mechanisms are easy targets for Huskar: 
Lich, 
Crystal Maiden, 
Silencer, 
Keeper of the Light, Venomancer, etc.
Additional:
* Huskar can easily regenerate lost health from DoT spells through 
Berserker's Blood rendering them ineffective
* Venomancer has little armor and mobility, and rarely builds Linken's Sphere, so he is quite vulnerable to 
Life Break.
Mars
* 
Burning Spear's magical damage is very troublesome for Mars in the laning stage.
* Life Break's percentage-based magical damage bypasses Bulwark, and can also be used to jump in or out of Arena Of Blood.
Venomancer
* Venomancer's damage-over-time abilities are easier to heal through with numerous Shadow Waves than other types of damage, and it's simple to time a Shallow Grave until the last possible second to save a teammate from them.
Mars
* Heroes that can save their allies can be a big problem for Mars: 
Dazzle, 
Omniknight.
Venomancer
* Fortune's End and False Promise easily dispel many crippling debuffs, such as Venomancer's Venomous Gale, or 
Skywrath Mage's 
Ancient Seal.
Additional:
* 
Fortune's End can dispel Venomous Gale and Poison Sting from allies.
* 
Fate's Edict grants 100% magic resistance to target, inhibiting the damage from Venomancer abilities.
Mars
* Heroes with high magical or pure damage will bypass Bulwark: 
Timbersaw, 
Dark Willow, 
Enigma, 
Invoker, Pugna, Skywrath Mage, 
Tinker, 
Zeus, 
Oracle.
Venomancer
* While 
Reincarnation is off cooldown, Poison Nova poses less of a threat as Wraith King will return with all debuffs cleared.
* 
Vampiric Spirit can out-heal the slow {tooltip:DoT|Damage over Time} from Poison Sting.
Mars
* 
Rage, acting as a pseudo-Black King Bar, completely negates Mars' initiation if used in time.
* 
Feast does damage and heals based on max health, perfect against high-health strength heroes like Mars.
* 
Infest allows Lifestealer to potentially save allies from Mars' initiation with a quick burst of extra health.
Venomancer
* Venomancer is a low health hero and low range hero who is easy to harass with Ion Shell on a creep in the early game.
* Venomancer depends entirely on all his slows to keep distance or chase, but since Surge ignores slows, it is nearly impossible for Venomancer to hunt or run away from Dark Seer or his surged teammates.
Mars
* 
Arcane Orb's pure damage ignores Mars' Bulwark.
* 
Astral Imprisonment can be used to stop Mars from being disruptive or save allies from his abilities.
* 
Sanity's Eclipse deals high damage to Mars, due to his low intelligence pool.
Mars
* 
Decay, 
Soul Rip and 
Flesh Golem all deal magical damage which ignores Bulwark.
* Decay reduces Mars' natural strength and therefore his health pool, which is what he relies on to trade effectively in lane.
Mars
* Rebound allows her to jump in or out of the Arena Of Blood. She can save her allies from the Arena with Dispose as well.
Mars
* It is difficult for Mars to trade blows with Ogre Magi in the early game thanks to his high base health, resistance and 
Ignite.
* 
Bloodlust can assist Ogre Magi or an ally in repositioning against Mars for its move speed bonus.
* 
Fireblast can interrupt and mitigate Mars from performing his skill combos, especially in combination with 
Multicast.
Venomancer
* Voodoo Restoration heals to counter damage over time of Poison Nova and Poison Sting.
Mars
* 
Shadowraze deals magic damage and ignores Bulwark.
* 
Requiem of Souls deals magic damage and can fear Mars away, forcing him to turn around and therefore become vulnerable.
Mars
* Necrophos' largely magical damage completely ignores Bulwark.
* 
Ghost Shroud protects Necrophos from God's Rebuke but more importantly stops Mars from being a threat in lane.
Mars
* Time Dilation while Spear of Mars and 
God's Rebuke are on cooldown will make these abilities unusable for a long time, rendering Mars nearly useless.
* Mars cannot turn inside the Chronosphere, which makes it easy to attack him from the back, bypassing Bulwark completely.
Additional:
* 
Time Walk allows Faceless Void to escape or enter Arena Of Blood, and helps him recover from Mars' burst damage.
* 
Time Lock's magical damage ignores Bulwark.
* 
Chronosphere allows Faceless Void to reposition behind Mars, ignoring his Bulwark while he is helplessly frozen in time.
Venomancer
* Venomous Gale is a great ganking and farming skill.
* 
Plague Ward serves as a flexible ability for pushing, ganking, farming and scouting. The innate Poison Sting also works on the stolen Plague Ward with half the damage.
* Poison Nova, if stolen and cast, puts a huge damage-over-time debuff on the enemy team, even greater than Venomancer himself with the help of 
Arcane Supremacy.
* 
Spell Steal has a greater cast distance than the effect area of Poison Nova, allowing Rubick to steal the spell while staying at the back.
* Venomancer suffers from mana pool problems, while Rubick has relatively high intelligence gain and can cast the same set of spells at ease.
Additional:
* All of Venomancer's abilities are decent choices for Rubick's Spell Steal. Stealing Plague Wards makes them apply Poison Sting as well.
Mars
* Mars' own father is a formidable foe because Zeus deals massive amounts of magical damage. The high damage, low cooldown nukes of 
Arc Lightning and 
Lightning Bolt combined with the percent health magic damage of 
Static Field will shred Mars' health because it bypasses Bulwark completely.
Mars
* 
Swashbuckle is an auto attack and therefore ignores Mars' Bulwark.
* 
Shield Crash upgraded with Aghanim is an auto attack and therefore ignores Mars' Bulwark.
* 
Rolling Thunder makes him immune to magic, making Pangolier able to roll in and out of Mars' Arena Of Blood.
Venomancer
* 
Dark Rift allows Underlord to transport allies from poison damage-over-time to the fountain.
* Underlord usually buys 
Pipe of Insight that gives a magic resistance to allies, inhibiting the damage from Venomancer abilities.
Mars
* 
Firestorm and 
Pit of Malice are very disruptive in team fights, completely matching Mars especially since it can all be cast inside Arena Of Blood and also does percentage-based magical damage, negating Bulwark.
* Dark Rift can save any allies of Underlord trapped in Arena Of Blood.
* 
Atrophy Aura allows Underlord to lane against Mars quite well since he does not have the best base damage during the early game.
* Underlord is a common carrier of both Pipe of Insight and 
Mekansm/
Guardian Greaves, allowing his team to combat Mars in the mid to late game.
Venomancer
* Heroes with strong area-of-effect damaging and/or disabling abilities will be able to intercept Underlord and his team when they exit from Fiend's Gate: 
Luna's Aghanim's Scepter upgraded 
Eclipse, 
Dawnbreaker's 
Solar Guardian, 
Axe's 
Berserker's Call, 
Mars's Arena of Blood, 
Jakiro's 
Macropyre, 
Dual Breath and 
Ice Path, 
Naga Siren's 
Song of the Siren, 
Razor's 
Eye of the Storm and 
Plasma Field, Lina's 
Light Strike Array, 
Broodmother's 
Spinner's Snare from Aghanim's Scepter, 
Elder Titan's 
Earth Splitter and 
Echo Stomp, 
Alchemist's 
Unstable Concoction and 
Acid Spray, 
Queen of Pain's 
Sonic Wave, 
Dark Seer's 
Wall of Replica and 
Vacuum, Venomancer's 
Noxious Plague and Poison Nova from Aghanim's Scepter, Oracle's Fortune's End and 
Rain of Destiny from 
Aghanim's Shard, 
Bloodseeker's 
Blood Rite, Enigma's 
Black Hole and 
Midnight Pulse, Shadow Fiend's Requiem of Souls, 
Batrider's Aghanim's Scepter upgraded 
Flaming Lasso, 
Firefly, 
Flamebreak and 
Sticky Napalm, Ancient Apparition's 
Ice Blast, 
Sand King's 
Epicenter, 
Sand Storm and 
Burrowstrike, 
Gyrocopter's 
Call Down, 
Ember Spirit's 
Sleight of Fist, 
Death Prophet's 
Exorcism and 
Silence, 
Monkey King's 
Wukong's Command, Crystal Maiden's 
Freezing Field, 
Muerta's 
The Calling, 
Medusa's 
Stone Gaze, Zeus's 
Nimbus from Aghanim's Scepter. Dark Willow's 
Bramble Maze, 
Pangolier's Swashbuckle, 
Grimstroke's 
Soulbind, 
Ink Swell and 
Stroke of Fate, 
Earthshaker's 
Echo Slam and 
Fissure, 
Puck's 
Dream Coil and 
Waning Rift, 
Winter Wyvern's 
Winter's Curse, 
Magnus's 
Reverse Polarity.
Mars
* Heroes with strong area-of-effect damaging and/or disabling abilities will be able to intercept Underlord and his team when they exit from Fiend's Gate: Luna's Aghanim's Scepter upgraded Eclipse, Dawnbreaker's Solar Guardian, Axe's Berserker's Call, Mars's Arena of Blood, Jakiro's Macropyre, Dual Breath and Ice Path, Naga Siren's Song of the Siren, Razor's Eye of the Storm and Plasma Field, Lina's Light Strike Array, Broodmother's Spinner's Snare from Aghanim's Scepter, Elder Titan's Earth Splitter and Echo Stomp, Alchemist's Unstable Concoction and Acid Spray, Queen of Pain's Sonic Wave, Dark Seer's Wall of Replica and Vacuum, Venomancer's Noxious Plague and Poison Nova from Aghanim's Scepter, Oracle's Fortune's End and Rain of Destiny from Aghanim's Shard, Bloodseeker's Blood Rite, Enigma's Black Hole and Midnight Pulse, Shadow Fiend's Requiem of Souls, Batrider's Aghanim's Scepter upgraded Flaming Lasso, Firefly, Flamebreak and Sticky Napalm, Ancient Apparition's Ice Blast, Sand King's Epicenter, Sand Storm and Burrowstrike, Gyrocopter's Call Down, Ember Spirit's Sleight of Fist, Death Prophet's Exorcism and Silence, Monkey King's Wukong's Command, Crystal Maiden's Freezing Field, Muerta's The Calling, Medusa's Stone Gaze, Zeus's Nimbus from Aghanim's Scepter. Dark Willow's Bramble Maze, Pangolier's Swashbuckle, Grimstroke's Soulbind, Ink Swell and Stroke of Fate, Earthshaker's Echo Slam and Fissure, Puck's Dream Coil and Waning Rift, Winter Wyvern's Winter's Curse, Magnus's Reverse Polarity.
Mars
* Heroes with high magical or pure damage will bypass Bulwark: Timbersaw, Dark Willow, Enigma, Invoker, Pugna, Skywrath Mage, Tinker, Zeus, Oracle.
Venomancer
* Any hero that can outrange Plague Ward can neutralize them without putting themselves at risk of receiving Poison Sting: Arc Warden, Chen, Clinkz, Drow Ranger, Lina, Mirana, Nature's Prophet, Pugna and Sniper.
* Special mention to heroes that outrange Plague Ward after obtaining talents that increase attack range.
Mars
* 
Ursa is a special mention because despite Bulwark diminishing most of the damage Ursa does, he is quite durable, especially with 
Enrage, discouraging the aggressive all-in playstyle of Mars; Ursa can simply not target Mars.
Mars
* Nukers who have set amounts of damage will really struggle against Lone Druid especially in True Form: Puck, 
Void Spirit, Mars.
Mars
* Heroes with high magical or pure damage will bypass Bulwark: Timbersaw, Dark Willow, Enigma, Invoker, Pugna, Skywrath Mage, Tinker, Zeus, Oracle.
Mars
* Heroes that depend on disrupting fights with ability combos or big ultimate abilities are vulnerable to the long stun of Fiend's Grip: 
Disruptor, Death Prophet, Enigma, 
Faceless Void, Invoker, Lich, Magnus, Mars, Medusa, 
Outworld Destroyer, 
Phoenix, Puck, Queen of Pain, Shadow Fiend, 
Treant Protector, 
Underlord, Winter Wyvern, 
Witch Doctor, Zeus.
Mars
* 
Kunkka's 
Ghostship and 
Torrent disrupt fights in Arena Of Blood.
Mars
* Heroes with high magical or pure damage will bypass Bulwark: Timbersaw, Dark Willow, Enigma, Invoker, Pugna, Skywrath Mage, Tinker, Zeus, Oracle.
Mars
* Heroes with high magical or pure damage will bypass Bulwark: Timbersaw, Dark Willow, Enigma, Invoker, Pugna, Skywrath Mage, Tinker, Zeus, Oracle.
Mars
* Heroes with high health especially Strength heroes will take more damage on Sun Ray: Axe, 
Pudge, 
Bristleback, Mars.
Mars
* Heroes with high magical or pure damage will bypass Bulwark: Timbersaw, Dark Willow, Enigma, Invoker, Pugna, Skywrath Mage, Tinker, Zeus, Oracle.
Venomancer
* 
Slardar can attack through Plague Wards and gain 
Bash of the Deep charges, and 
Templar Assassin can spill 
Psi Blades through Plague Wards too.
Mars
* Heroes with high magical or pure damage will bypass Bulwark: Timbersaw, Dark Willow, Enigma, Invoker, Pugna, Skywrath Mage, Tinker, Zeus, Oracle.
Venomancer
* Heroes with damage-over-time abilities easily allow Bristleback to turn his back in order to proc 
Bristleback continuously and to massively reduce to damage dealt to him: Arc Warden, Venomancer, Luna.
Venomancer
* Any hero that can outrange Plague Ward can neutralize them without putting themselves at risk of receiving Poison Sting: Arc Warden, Chen, Clinkz, Drow Ranger, Lina, Mirana, Nature's Prophet, Pugna and Sniper.
* Special mention to heroes that outrange Plague Ward after obtaining talents that increase attack range.
Mars
* Solar Guardian can save allies caught inside Arena of Blood.
Venomancer
* Due to her slow movement speed,heroes with crowd control and slows can shut down Dawnbreaker:
Lion, Crystal Maiden ,Venomancer etc.
Mars
* 
Blink Strike gives bonus backstab damage and can bypass Bulwark. Defensively, it could be used to teleport away from Mars, especially while inside Arena of Blood.
* 
Smoke Screen can interrupt Mars' skill combos, especially when cast inside Arena of Blood.
* 
Tricks of the Trade can be used to evade Mars' skills, which have a slight delay to them. It could also be used to buy himself time while trapped inside of Arena of Blood.
Additional:
* Bulwark is generally irrelevant against Riki as he primarily deals bonus damage from behind.
Mars
* Heroes who rely on their target to run away: 
Riki, 
Bounty Hunter.
Venomancer
* Venomancer's damage-over-time abilities do little damage against Counterspell.
* Blink helps Anti-Mage get away from Venomancer's slows.
Additional:
* 
Counterspell provides magic resistance, diminishing the effectiveness of Venomancer's spells.
* Venomancer's lack of hard disable allows Anti-Mage to use 
Blink, circumventing the slows Venomancer depends on.
Mars
* Heroes who cannot fight back during Arena of Blood in the early and mid game: 
Abaddon, 
Anti-Mage, Broodmother, Luna, Sniper, 
Troll Warlord, 
Weaver, Clinkz.
Venomancer
* Teleportation allows Natures Prophet to save himself from the damage over time of Venomous Gale, Poison Sting and Poison Nova.
* Plague Wards can be destroyed with Nature's Prophet's Treants.
Mars
* Heroes who lack burst damage will have a hard time against Mars: 
Phantom Lancer, Nature's Prophet, Lich.
Venomancer
* 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.
Mars
* 
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.
Mars
* 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.
Venomancer
* Venomancer's magical damage-over-time poisons will constantly put Tree Dance on cooldown, greatly diminishing Monkey King's mobility.
* Venomous Gale and Poison Nova will hit Monkey King when he is perched on a tree, or disguised with Mischief.
* However, Venomancer is also easily ganked by Monkey King if caught by surprise.
Additional:
* Venomancer's magical damage-over-time poisons putting 
Tree Dance on cooldown, greatly diminishing Monkey King's mobility.
* Venomous Gale and Posion Nova will hit Monkey King when he is perched on a tree, or disguised by 
Mischief.
Mars
* If visible, Mars can knock Monkey King off his Tree Dance with God's Rebuke, as well as Spear of Mars. Arena of Blood also destroys a large swath of trees, which can disrupt Monkey King's positioning and turn him vulnerable should he choose to hide in trees.
* Mars can endure 
Jingu Mastery attacks simply by facing him with Bulwark.
* Mars can end Wukong's Command early by displacing Monkey King with a well-thrown Spear of Mars. Mars can also endure most of his clones with Bulwark.
Additional:
* Monkey King's natural reliance on trees makes him an exceptionally prime target for Spear of Mars. Should Monkey King use Mischief to disguise himself, it will still hit him, stunning him in the process.
* God's Rebuke easily pushes Monkey King out of Wukong's Command.
Venomancer
* Venomancer's poison damage over time is very effective against Spectre, who tends to lack magic resistance during the early to mid game.
* Venomancer's multiple slows greatly reduces Spectre's movement speed and mobility.
* Plague Wards can scout out Spectre while she is hiding in trees.
Additional:
* Venomancer's poison damage-over-time are very effective against Spectre, which is lack of magic resistance from early to mid game.
* Venomancer's multiple slows greatly reduces Spectre's low mobility, even through 
Spectral Dagger.
* Plague Wards reveals Spectre while she is hiding on trees.
Mars
* Spectre cannot have a good game if she is pressured heavily in lane, which is something Mars can do. He may even force her to cast 
Haunt as an escape, putting it on a long cooldown.
* Should Spectre get to the late game, Mars can block a large amount of her damage with Bulwark and can mitigate some of the chaos caused by her Haunt illusions with God's Rebuke.
Venomancer
* Aggressively Poofing and Earthbinding is not going to end well against Venomancer, as he will be an easy target for Noxious Plague.
* Venomancer's constant slows greatly reduce Meepo's mobility.
Mars
* Bulwark blocks the attack from Meepo and his clones.
* Spear of Mars & God's Rebuke prevents Meepo and his clones from initiation or escaping.
Venomancer
* Plague Wards may reveal a hiding Techies. If there's a sentry nearby, they may also reveal a stack of mines hidden in a juking spot.
Mars
* Heroes with forced movement abilities or non-interrupting forced movement, such as Lion, Drow Ranger, Magnus, Mars, as they can cancel blast-off mid air, removing his ability to initiate or escape.
Venomancer
* Similar to Night Stalker, Venomancer can simultaneously scout Magnus hiding in trees and put Blink Dagger on cooldown with Plague Ward, which gives Magnus problems when trying to blink in and initiate.
Additional:
* Venomancer can simultaneously scout Magnus hiding in trees and putting Blink Dagger on cooldown with Plague Wards, which makes Magnus real problems to blink and initiate.
Mars
* 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.
Venomancer
* Heroes that can apply early pressure before Phantom Assassin has farm are massive threats: Axe, Viper, 
Meepo, Jakiro, Pugna, 
Slark, Venomancer etc.
Mars
* Phantom Assassin's high physical damage is greatly reduced by Bulwark.
* God's Rebuke has true strike, ignoring the evasion from 
Blur.
Venomancer
* Venomancer's magical damage-over-time poisons greatly reduce Bounty Hunter's mobility.
* Venomous Gale, combined with Plague Wards and Poison Nova with True Sight items can allow Venomancer and his teammates to gank Bounty Hunter while he is roaming alone.
Mars
* Heroes who rely on their target to run away: Riki, Bounty Hunter.
Venomancer
* Heroes that can slow Charge of Darkness by a huge amount: Venomancer, Viper, Dazzle, Arc Warden, Lion, Huskar, Shadow Shaman, 
Visage, 
Undying, Jakiro.
Mars
* Durable heroes: Axe, Dawnbreaker, Bristleback, Mars, Omniknight, Tidehunter, Wraith King, 
Primal Beast, Underlord.
Venomancer
* 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.
Venomancer
* Unless Puck is facing the direction he wants to blink while in Phase Shift, the Venomous Gale and Noxious Plague combo consistently ticks many times over several seconds, making it very difficult to use Blink Dagger towards the other direction. Puck's slow turning rate makes this even worse.
* Venomancer can use Plague Wards to reveal Puck's position before he even gets a chance to initiate.
Mars
* Bulwark mitigates 
Omnislash which deals physical damage, severely reducing its damage.
* Omnislash switch to opposite direction with each slash, so Mars can easily reduce most of its damage.
* However because {Ability ID:Blade Fury|Juggernaut} gives spell immunity Juggernaut can easily escape from {Ability ID:Arena Of Blood|Mars}.
Additional:
* Juggernaut deals mostly physical damage, which is easily mitigated with Bulwark.
* Juggernaut's Omnislash switches to opposite directions which each slash, so Mars can mitigate most of its damage since he only takes full damage from one direction: his back.
Mars
* 
Shukuchi cannot help Weaver escape from Arena of Blood, and can most likely die if detected through invisibility.
* If pinned to the arena's walls, 
Time Lapse tends to not be enough to save Weaver, as God's Rebuke can keep him burst down thanks to its damage scaling.
* 
The Swarm and 
Geminate Attack are not enough to pierce through Bulwark.
Venomancer
* Due to lack of magic resistance, Venomancer poisons eats through Windranger's health.
Additional:
* Due to lack of magic resistance, Venomancer abilities eats through Windranger's health.
* Venomancer's multiple slows, to an extent, negates Windrun's mobility.
Venomancer
* Venomancer's slows and magical damage-over-time works well against Earthshaker's which completes lack of mobility.
* Plague Wards are useful for slowing and kitting down Earthshaker, revealing him from initiating and re-initiating and putting his Blink Dagger on cooldown if Venomancer has vision over Earthshaker.
Additional:
* Earthshaker can be kited by Venomancer's slows, which is lack of mobility.
* Plague Wards is very useful for slowing and kitting down Earthshaker, revealing him from initiating and re-initiating and putting his Blink Dagger on cooldown.
Mars
* Arena Of Blood prevents Bloodseeker from attacking a 
Ruptured target.
* Bulwark helps Mars survive Rupture ganks simply by turning towards Bloodseeker without moving.
* Spear of Mars and God's Rebuke can push Bloodseeker from Ruptured targets.
Venomancer
* Venomous Gale, Poison Sting and Poison Nova deal damage over time and will chip away at Gravekeeper's Cloak in addition to slowing an already sluggish hero.
* Venomancer's normal attacks deal Poison Sting and will chip away at Gravekeeper's Cloak.
Mars
* Heroes who lack burst damage will have a hard time against Mars: Phantom Lancer, Nature's Prophet, Lich.
Venomancer
* Heroes that commonly attack ethereal units will not have any problems against Muerta's Pierce The Veil: Tinker, Jakiro, Lina, Luna, Pugna or Ogre Magi, Enigma, Batrider, 
Techies, Broodmother, Dawnbreaker, Shadow Shaman, 
Bane, Tinker, Venomancer, Arc Warden.
Mars
* Heroes who can disable Mars but cannot do any damage to him, meaning he just tanks their abilities: 
Doom, Magnus.
Mars
* Heroes that can negate Hoodwink's mobility: Kunkka, Disruptor, Mars.
Venomancer
* In general, heroes that can slow down Dragon Knight's movement speed will do well against him. This includes Venomancer and others in addition to the heroes mentioned above.
Mars
* Heroes who cannot fight back during Arena of Blood in the early and mid game: Abaddon, Anti-Mage, Broodmother, Luna, Sniper, Troll Warlord, Weaver, Clinkz.
Venomancer
* Heroes who rely on damage over time as Spiked Carapace can block and reflect only one instance of damage: Jakiro, Viper, Venomancer, Huskar, Ember Spirit, Dark Seer, Sand King, Doom, Dawnbreaker. However, this also means they are easily stunned.
Mars
* Heroes who cannot fight back during Arena of Blood in the early and mid game: Abaddon, Anti-Mage, Broodmother, Luna, Sniper, Troll Warlord, Weaver, Clinkz.
Mars
* Heroes that are hard to gank: Axe, Death Prophet, Phantom Lancer, Slark, 
Centaur Warrunner, Bristleback, Medusa, Mars.
Mars
* Heroes who lack burst damage will have a hard time against Mars: Phantom Lancer, Nature's Prophet, Lich.
Mars
* Heroes who cannot fight back during Arena of Blood in the early and mid game: Abaddon, Anti-Mage, Broodmother, Luna, Sniper, Troll Warlord, Weaver, Clinkz.
Venomancer
* Heroes who thrive on teamfights can be a problem, such as Venomancer, 
Necrophos, Centaur Warrunner...
Mars
* Heroes that are hard to gank: 
Dragon Knight, Mars, Centaur Warrunner.
Mars
* Heroes with the capability of removing or destroying trees greatly hinders the effectiveness of Treant Protector's abilities: Batrider, Nature's Prophet, Lina, Enigma, Mars
Venomancer
* Any hero that can outrange Plague Ward can neutralize them without putting themselves at risk of receiving Poison Sting: Arc Warden, Chen, Clinkz, Drow Ranger, Lina, Mirana, Nature's Prophet, Pugna and Sniper.
* Special mention to heroes that outrange Plague Ward after obtaining talents that increase attack range.
Venomancer
* Venomancer's damage over time can force Chen to use Hand of God prematurely, potentially wasting a chance to save his allies during a teamfight.
* Venomancer's Poison Nova, Venomous Gale and Plague Ward can easily kill Chen's creeps.
Venomancer
* Sunder can prevent Terrorblade's or an ally's death by swapping health, making damage-over-time abilities inefficient. Heroes that rely on damage-over-time abilities like Venomancer and Huskar will have a hard time against Sunder.
Additional:
* 
Reflection illusion will apply Poison Sting back towards Venomancer.
* 
Conjure Image and 
Metamorphosis will make quick work of Plague Wards.
* While ticking down from Poison Nova, Terrorblade can wait until the last possible moment to 
Sunder a target, either friend or foe.
Mars
* Bulwark negates most of the physical damage from Terrorblade and his illusions.
* God's Rebuke and Spear of Mars can decimate Terrorblade's illusions quickly.
Venomancer
* Slardar can attack through Plague Wards and gain Bash of the Deep charges, and Templar Assassin can spill Psi Blades through Plague Wards too.
Venomancer
* Venomancer's entire arsenal deals lingering damage over a long time and therefore burns through her Refraction very quickly. Not only that, his persistent slow from Poison Sting (it can be re-applied again and again with Plague Ward) allows his team to catch up to her even with the disruption from her Psionic Trap.
Additional:
* Venomous Gale and Plague Wards allow to quickly melt through 
Refraction charges.
* Both Poison Nova and Venomous Gale hit invisible units, so 
Meld cannot be used defensively.
Venomancer
* Any hero that can outrange Plague Ward can neutralize them without putting themselves at risk of receiving Poison Sting: Arc Warden, Chen, Clinkz, Drow Ranger, Lina, Mirana, Nature's Prophet, Pugna and Sniper.
* Special mention to heroes that outrange Plague Ward after obtaining talents that increase attack range.
Mars
* As long as Mars is facing her with Bulwark, even if pushed away with 
Gust, Drow Ranger will do no effectual damage against him. Mars' ability to endure her onslaught usually gives him enough time to cast Arena of Blood, of which she has a very slim chance surviving without Gust.
* With Bulwark's active ability, Mars can protect allies pursued by Drow Ranger by redirecting her projectiles to his shield instead.
Mars
* Medusa's Stone Gaze forces Mars to choose between getting petrified, or turning his vulnerable back on Medusa.
Mars
* Bulwark can make each of Medusa's attacks target him instead, reducing Medusa's contribution on team fights.
* Spear of Mars stuns Medusa and also pushes her away from teamfights, taking advantage of Medusa's low mobility.
* Arena Of Blood blocks Medusa's attacks from outside the arena.
Mars
* Sticky Napalm slows turn rate, making it difficult for Mars to face frontwards, where Spear of Mars and Bulwark are effective. In combination with Firefly, which deals magic damage, Batrider can make quick work of Mars.
* Flaming Lasso disables Mars while enemies re-position themselves behind Mars to avoid Bulwark.
Venomancer
* Plague Wards are very hard for Batrider to play against as they provide a lot of vision as well as disable Blink Dagger for a long duration.
Venomancer
* Sniper can easily destroy Plague Ward from long range.
Mars
* Even if he can slow Mars down with 
Shrapnel and 
Headshot, Mars can tank Sniper's physical damage simply by facing him with Bulwark, allowing him to endure his auto-attacks into the late-game. Should Sniper choose to attack someone else, Mars can redirect his projectiles with Bulwark's active ability.
* Sniper's poor mobility makes him very vulnerable to Arena of Blood, especially in the early game. Mars can also take advantage of this by pushing him closer to the front line with Spear of Mars.
Venomancer
* 
Dark Pact can dispel Venomous Gale and Poison Sting.
* 
Shadow Dance allows Slark heightened regeneration when out of vision making DoTs effects less threatening.
Mars
* Bulwark blocks much of Slark's basic attack damage, even during Shadow Dance.
* Slark finds it very difficult to have a good early/mid game when pressured in the early game by Spear of Mars and God's Rebuke.
* Spear of Mars and God's Rebuke can hit Slark through Shadow Dance and 
Depth Shroud.
* Should 
Pounce be on cooldown, Slark is very vulnerable inside Arena of Blood.
Venomancer
* Any hero that can outrange Plague Ward can neutralize them without putting themselves at risk of receiving Poison Sting: Arc Warden, Chen, Clinkz, Drow Ranger, Lina, Mirana, Nature's Prophet, Pugna and Sniper.
* Special mention to heroes that outrange Plague Ward after obtaining talents that increase attack range.
Mars
* Heroes who cannot fight back during Arena of Blood in the early and mid game: Abaddon, Anti-Mage, Broodmother, Luna, Sniper, Troll Warlord, Weaver, Clinkz.
Mars
* Berserker's Call forces Mars to face in the direction choosen.
* 
Counter Helix deals pure damage and can go through Bulwark.
Venomancer
* Venomancer's slows and magical damage-over-time work well against Axe's complete lack of mobility.
* Plague Ward is especially useful for slowing down Axe, and revealing him before he initiates, as well as putting his Blink Dagger on cooldown.
Additional:
* Venomancer's slows and magical damage-over-time work well against Axe's complete lack of mobility.
* Plague Wards is especially useful for slowing down Axe, and revealing him before he initiates, as well as putting his Blink Dagger on cooldown.
* For the same reasons, Venomancer is a good ally for Axe when the situation is reversed.
Mars
* Heroes that can save their allies can be a big problem for Mars: Dazzle, Omniknight.
Venomancer
* Heroes who can harass Omniknight out of lane will keep him weak in the mid game: Viper, Venomancer, Clinkz.
Venomancer
* Heroes that deal damage over time will also fail to bring down Abaddon and his allies, such as Huskar, Venomancer, or Phoenix.
Additional:
* 
Borrowed Time & 
Aphotic Shield can dispel Venomous Gale and Poison Sting.
Mars
* Heroes who cannot fight back during Arena of Blood in the early and mid game: Abaddon, Anti-Mage, Broodmother, Luna, Sniper, Troll Warlord, Weaver, Clinkz.
Venomancer
* Venomancer has low health, which makes him vulnerable to Lina's heavy magic damage.
Plague Wards easily in all stages of the game.
* Fiery Soul attack speed bonus removes
Mars
*
Dragon Slave deals reliable magic damage during the laning phase against Mars.
Eul's Scepter of Divinity and 
Light Strike Array combo can interrupt Mars from being disruptive for a decent amount of time and leave him vulnerable for follow up stuns.
Laguna Blade deals massive magical damage, and pure damage with 
Aghanim's Scepter.
* Lina's
*