* Guardian Angel completely negates all of Lycan's damage since Lycan mainly deals physical damage.
* Purification can also be a problem for Lycan, as Purification deals damage around the target, which poses a problem for him and his summons.

* Heroes that can save their allies can be a big problem for Mars: Dazzle, Omniknight.

* Tidebringer's cleave will cripple any of his summons.
* Could potentially build Heaven's Halberd to cripple Lycan even more.
Additional:
* Tidebringer can be used to kill Lycan's summons.
* Can also build into Heaven's Halberd which will disable Lycan's auto attacks, crippling him even more.

* Kunkka's Ghostship and Torrent disrupt fights in Arena Of Blood.

* Can cast Demonic Conversion on one of Lycan's Wolves, making this a numbers fight.
* Malefice will greatly reduce his ability to engage
* Midnight Pulse can steep an area making it harder for Lycan to engage in.

* Heroes with high magical or pure damage will bypass Bulwark: Timbersaw, Dark Willow, Enigma, Invoker, Pugna, Skywrath Mage, Tinker, Zeus, Oracle.

* Heroes with summoned units don't fare well against Dawnbreaker. (Phantom Lancer ,Beastmaster ,Lycan).

* Solar Guardian can save allies caught inside Arena of Blood.

* Melee heroes who rely on summons, illusions, or clones will trigger Counter Helix more often, thus taking more damage: Meepo, Lycan, Phantom Lancer

Additional:
* Berserker's Call can keep Lycan in place during his Shapeshift even through Black King Bar.
* Counter Helix is very effective against Lycan because of his summons.
* Culling Blade will prevent Lycan from running away with Shapeshift when he drops low.

* Berserker's Call forces Mars to face in the direction choosen.
* Counter Helix deals pure damage and can go through Bulwark.

* Pugna's Decrepify prevents the target from taking physical damage or doing damage, which poses a huge problem for Lycan, as he mainly deals physical damage.

* 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.

* All of Timbersaw's spells deal AoE damage, killing Lycan's summons very quickly.
* Reactive Armor will gain stacks quickly because of Lycan's summons.

* Heroes with high magical or pure damage will bypass Bulwark: Timbersaw, Dark Willow, Enigma, Invoker, Pugna, Skywrath Mage, Tinker, Zeus, Oracle.

* Heroes who have summons, which can be quickly cleared by his powerful area of effect skill: Nature's Prophet, Enigma, Lycan

* 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.

* Heroes with summons and illusions can find themselves easily bested by Lina, like Broodmother, Nature's Prophet, Chen, Terrorblade, Naga Siren, Visage, Wraith King, Lycan, Phantom Lancer, Shadow Shaman.

* Dragon Slave deals reliable magic damage during the laning phase against Mars.
* Lina's 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.

* Faceless Void can lock Lycan down with his Chronosphere pinning him down as long as his ultimate is up.

* 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.

* Arctic Burn allows Winter Wyvern to escape Lycan, even when he uses his ultimate.
* Splinter Blast is very effective in dealing with Lycan's summons.
* Cold Embrace saves allies from Lycan's raw physical damage and can buy allies enough time to turn the tide of battle.
* Winter's Curse stops Lycan in his tracks and is very effective because of his summons.
Additional:
* All of Lycan's damage is physical which is totally negated by Cold Embrace.
* Lycan often moves around with large amount of creeps, wolves created by Summon Wolves and neutral creep dominated by Helm of the Dominator which can be easily cleared by Splinter Blast or used as a great source of damage by Winter's Curse. If you catch Lycan with creeps nearby and affected by Shapeshift using Winter's Curse on him will most certainly end up with his death.

* 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.

* 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.

* Brewmaster can waste a large portion of Lycan's ultimate by putting him in Cyclone.
* Lycan has no way to stop Brewmaster from using Primal Split by himself.
* Lycan's team often tries to push towers as a group, and Brewmaster excels at winning teamfights while trying to defend a tower.

* 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.

* 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.

* Venomancer's spells all deal magical damage, ignoring Bulwark.
* Venomancer's multiple slows are especially effective at kiting Mars.
* Plague Ward can attack through Arena Of Blood.
Additional:
* Venomancer's poison attacks are all magical damage, ignoring Bulwark.
* Venomancer's multiple slows are especially effective against Mars' low mobility.
* Plague Wards can attack through Arena of Blood.

* 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.

* 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.

* Paralyzing cask bounces between him and his wolves, keeping him stunned for long amounts of time.

* A well landed Fissure can potentially take Lycan out of the fight for several seconds, who heavily relies on precious seconds from Black king bar and Shapeshift to fight.
* Aftershock reduces the effectiveness of his summons and can prove quite irritating for Lycan.
* Echo Slam is very powerful with the sheer amount of Lycan's units and will cause him to think twice when pushing towers.

* Kraken Shell grants him massive physical attack protection
* Anchor Smash will wipe the area, clearing Lycan's wolves.

* Lycan is a hero focused entirely on single target physical damage and lacks disables or AoE damage. Due to this, he will have difficulties dealing with illusions or Naga Siren's Ensnare.

* Primal Roar allows Beastmaster to keep Lycan in place after he used his Shapeshift.

* Lycan's wolves deal little damage to Bristleback, and are easily killed by Quill Spray, even when they're invisible.
* Lycan's lack of burst damage makes it very hard for him to kill Bristleback, especially when his back is turned.
Additional:
* Quill Spray can be used to kill Lycan's summons.
* Bristleback allows him to stay alive against Lycan while dishing out counter attacks
* He can overpower Lycan with his Warpath instead.

* 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.

* Great Cleave will kill Lycan's summons very rapidly.
* Warcry will allow Sven and his allies to tank Lycan's damage, which is mainly physical.
* Storm Hammer will damage and stun Lycan's as well as his summons.

* 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.

* Her Mana Shield is too tough for Lycan to break.
* Mystic Snake can hit for a massive damage once it spread between his summons.
Additional:
* Can be easily petrified despite his speed.
* Summoned wolves will be targeted by Split Shot or Mystic Snake

* Medusa's Stone Gaze forces Mars to choose between getting petrified, or turning his vulnerable back on Medusa.

* Heroes with high magical or pure damage will bypass Bulwark: Timbersaw, Dark Willow, Enigma, Invoker, Pugna, Skywrath Mage, Tinker, Zeus, Oracle.

* Heroes with high magical or pure damage will bypass Bulwark: Timbersaw, Dark Willow, Enigma, Invoker, Pugna, Skywrath Mage, Tinker, Zeus, Oracle.

* Heroes that can summon units will have their summons destroyed very quickly if badly micro-managed, like Chen, Lycan, and Phantom Lancer.

* Heroes with high health especially Strength heroes will take more damage on Sun Ray: Axe, Pudge, Bristleback, Mars.

* Heroes with high magical or pure damage will bypass Bulwark: Timbersaw, Dark Willow, Enigma, Invoker, Pugna, Skywrath Mage, Tinker, Zeus, Oracle.

* Nukers who have set amounts of damage will really struggle against Lone Druid especially in True Form: Puck, Void Spirit, Mars.

* Heroes with high magical or pure damage will bypass Bulwark: Timbersaw, Dark Willow, Enigma, Invoker, Pugna, Skywrath Mage, Tinker, Zeus, Oracle.

* Heroes who summon multiple units that are not spell immune. Nature's Prophet,Lycan,Beastmaster

* Jakiro's area-of-effect abilities make him strong against heroes who rely on illusions and summons: Terrorblade, Naga Siren Chaos Knight, Phantom Lancer, Broodmother, Nature's Prophet, Lycan, Wraith King, Visage.

* Heroes that heavily depend on illusions or summons, (Naga Siren, Terrorblade, Phantom Lancer, Lycan,...) are vulnerable to Sleight of Fist and even more so if Ember Spirit has Battle Fury.

* Dragon Knight's insanely high armor and splash damage can cause Lycan to struggle taking him down.

* Heroes that can save their allies can be a big problem for Mars: Dazzle, Omniknight.

* Heroes who rely heavily on melee attacks and lack early spell immunity are easily blocked and interrupted by Ink Swell: Lycan, Ursa, Troll Warlord.

Additional:
* Stroke of Fate deals more damage when it hits more targets which makes it very effective in dealing with Lycan and his units.
* Soulbind prevents Lycan from running away and makes him very easy to deal with.

* 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.

* 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.

* 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.

* 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.

* 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.

* 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.

* Lycan relies heavily on right clicks making Untouchable very effective against him.
* If he tries to run away Impetus will do huge amounts of damage.
Additional:
* She can Enchant one of the wolves to her side.
* Lycan will struggle greatly to harm Enchantress through her Untouchable which can seriously slow down Lycan's attack speed even if Lycan is spell immune.

* Heroes who rely on summons will see them destroyed easily by Overwhelming Odds: Lycan, Arc Warden, Warlock, Chen

* 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.

* Phantom Assassin's Blur is a real problem for Lycan, as he relies entirely on direct attacks to deal damage.

* Lycan cannot escape from a Pounce even if he uses Shapeshift, and has no disabling abilities to stop Slark.

* Any Hero with high mobility will be neutralized by dream coil: Queen of Pain, Storm Spirit, Ember Spirit, Lycan, Bloodseeker, Anti-Mage, Timbersaw.

* 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.

* Charge of Darkness allows Spirit Breaker to catch up to Lycan after he uses Shapeshift.
Additional:
* Vision from Charge of Darkness will easier to catch Lycan Shapeshift and Charge of Darkness out of reach Lycan Summon Wolves and Lycan's other creeps. Until upgrade Aghanim's Scepter faster catching Lycan Shapeshift.

* Heroes who rely on physical damage output to be effective will fare badly against Muerta's Pierce the Veil: Phantom Assassin, Terrorblade, Drow Ranger, Lifestealer, Anti-Mage, Alchemist, Lycan, Clinkz, Sniper.

* Keeper of the Light has a blind, which causes Lycan to miss his attacks.

* Heroes with high magical or pure damage will bypass Bulwark: Timbersaw, Dark Willow, Enigma, Invoker, Pugna, Skywrath Mage, Tinker, Zeus, Oracle.

* 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.

* Heroes with break abilities: Shadow Demon (with Aghanim's Scepter), Viper.

* 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.

* Rupture completely negates Lycan's high mobility.
* All of Lycan's summons are good sources of healing with Bloodrage.
Additional:
* Rupture completely negates Lycan's high mobility.
* All of Lycan's summons are good sources of healing with Bloodrage.

* Treant Protector grants protection against his attacks with Living Armor and his ultimate, Overgrowth is a massive AoE disarm and root that pierces spell immunity, causing trouble to Lycan. You will find yourself in need of an ally's dispel or forced to pop Black King Bar for its dispel.

Additional:
* Lycan has no kind of teleport, being only able to walk, and heavily relies on his attacks. As Overgrowth roots and disarms the targets, Lycan can't do much in an overgrowth field.