Sand King
* Ghostship helps your team soak up damage from 
Epicenter, especially if he initiates during the battle.
* 
Sand King can't dodge X Marks the Spot - Torrent combo by his abilities. Torrent drags him out of his 
Sand Storm
Mars
* 
Kunkka's 
Ghostship and 
Torrent disrupt fights in Arena Of Blood.
Sand King
* Sand King has nothing to deal with 
Supernova, as none of his spells are effective.
* The damage-over-time abilities of Phoenix disable Sand King's 
Blink Dagger very often.
Mars
* Heroes with high health especially Strength heroes will take more damage on Sun Ray: 
Axe, 
Pudge, 
Bristleback, 
Mars.
Mars
* 
Berserker's Call forces Mars to face in the direction choosen.
* 
Counter Helix deals pure damage and can go through Bulwark.
Sand King
* 
Lifestealer's Rage negates Sand King's spells which do magical damage.
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.
Sand King
* Heroes that rely on slows to get kills: Lifestealer, 
Night Stalker, 
Ursa, 
Phantom Assassin, 
Terrorblade.
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
* 
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.
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.
Sand King
* 
Boulder Smash will push Sand King out of Sand Storm to reveal his position or an activated Epicenter off of Earth Spirit's allies, potentially wasting his combo
* 
Rolling Boulder and 
Geomagnetic Grip allow Earth Spirit to easily stun and silence Sand King and interrupt the channeling of Epicenter, completely ruining his initiation.
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.
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.
Sand King
* 
Ravage, being an AoE disable, cancels Epicenter's channeling from a long range, limiting his potential to counter-initiate.
* This can be remedied, however, by first using a Black King Bar, then channel Epicenter, then finally initiate with Blink Dagger.
Mars
* Solar Guardian can save allies caught inside Arena of Blood.
Sand King
* Both 
Arcane Curse and 
Last Word punishes casters with spammable spells such as Sand King.
* As a strength caster, 
Intelligence Steal reduces Sand King's mana pool even more.
* 
Global Silence silences Sand King, effectively reducing Sand King's initiation and counter-initiation potential. It can also interrupt channeling of Epicenter.
Sand King
* 
Pugna's 
Nether Ward damages Sand King when he channels Epicenter, preventing him from using Blink Dagger afterward.
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.
Sand King
* Heroes with no mobility will take some good damage from Sand King's spells: 
Dragon Knight, 
Jakiro, Pugna, 
Earthshaker.
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.
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.
Sand King
* Burrowstrike is one of the best and easiest steals for Rubick and Sand King should be careful when playing against him - it's much better to give away Sand Storm.
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.
Sand King
* Quill Spray will hit Sand King inside Sand Storm, damaging him and putting Sand King's Blink Dagger on cooldown, preventing him from escaping.
* Epicenter's numerous damage ticks will trigger Bristleback's passive repeatedly during teamfights.
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.
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.
Mars
* 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.
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.
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 can save their allies can be a big problem for Mars: 
Dazzle, 
Omniknight.
Mars
* Heroes with high magical or pure damage will bypass Bulwark: Timbersaw, Dark Willow, Enigma, Invoker, Pugna, Skywrath Mage, Tinker, Zeus, Oracle.
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
* Heroes with break abilities: 
Shadow Demon (with Aghanim's Scepter), 
Viper.
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 magical or pure damage will bypass Bulwark: Timbersaw, Dark Willow, Enigma, Invoker, Pugna, Skywrath Mage, Tinker, Zeus, Oracle.
Mars
* Heroes that can save their allies can be a big problem for Mars: Dazzle, Omniknight.
Mars
* Heroes with high magical or pure damage will bypass Bulwark: Timbersaw, Dark Willow, Enigma, Invoker, Pugna, Skywrath Mage, Tinker, Zeus, Oracle.
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.
Sand King
* Phantom Assassin relies on her 
Blur to stay alive, but is very vulnerable to Sand King's heavy magic damage.
* With Burrowstrike, Sand King can often catch Phantom Assassin before she can use her Black King Bar.
* Sand King can dodge 
Stifling Dagger with Sandstorm.
* Phantom Assassin has a hard time killing Sand King because of his high mobility.
Mars
* Phantom Assassin's high physical damage is greatly reduced by Bulwark.
* God's Rebuke has true strike, ignoring the evasion from Blur.
Sand King
* All of Sand King's abilities deal AoE damage.
* However, Epicenter is usually a non-issue against Doppelganger.
Mars
* Heroes who lack burst damage will have a hard time against Mars: 
Phantom Lancer, 
Nature's Prophet, Lich.
Sand King
* Heroes that rely on slows to get kills: Lifestealer, Night Stalker, Ursa, Phantom Assassin, Terrorblade.
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.
Sand King
* Sand King's 
Caustic Finale combined with Sand Storm will kill Treants easily.
* Sand King can interrupt Teleportation with 
Burrowstrike, even through Sprout.
Additional:
* With Caustic Finale, Sand King can easily kill the treants from 
Nature's Call.
* Burrowstrike allows Sand King to prevent Nature's Prophet from using 
Teleportation inside of his 
Sprout.
Mars
* Heroes who lack burst damage will have a hard time against Mars: Phantom Lancer, Nature's Prophet, Lich.
Sand King
* Sand King is a strong ganker, allowing him to shut down squishy heroes in the early game: Phantom Assassin, 
Clinkz, 
Sniper, 
Enchantress.
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.
Sand King
* Burrowstrike allows Sand King to escape from 
Eclipse or to close the gap on Luna and finish her off.
* Sand Storm allows Sand King to harass Luna more efficiently than she does with 
Lucent Beam, as it makes him invisible for it's duration and while in it, rendering him safe from both, Lucent Beam and Eclipse and forcing Luna to buy 
Dust of Appearance more often.
* Caustic Finale allows Sand King to deal serious damage to both, Luna and her allies, which is especially hazardous in laning stage as Luna's attack range is short.
* Epicenter combined with Burrowstrike and Sand Storm can often kill Luna before she can do anything because of her low health and strength gain.
* Overall, Sand King forces Luna to play more defensively instead of offensively, and for the same reasons, Sand King makes a very powerful ally for Luna when they are in the same team.
Additional:
* Burrowstrike allows Sand King to escape from Eclipse or to close the gap on Luna and finish her off.
* Sand Storm allows Sand King to harass Luna more efficiently than she does with Lucent Beam, as it makes him invisible for it's duration and while in it, rendering him safe from both, Lucent Beam and Eclipse and forcing Luna to buy Dust of Appearance more often.
* Caustic Finale allows Sand King to deal serious damage to both, Luna and her allies, which is especially hazardous for Luna during the laning stage as Luna's attack range is short.
* Epicenter combined with Burrowstrike and Sand Storm can often kill Luna before she can do anything because of her low health and strength gain.
* Overall, Sand King forces Luna to play more defensively instead of offensively, and for the same reasons, Sand King makes a very powerful ally for Luna when they are in the same team.
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.
Sand King
* Heroes with powerful area-of-effect disables can initiate on Meepo and his clones and shut him down, such as Enigma, Invoker, Magnus, Puck, and Sand King.
Additional:
* Burrowstrike can stun multiple Meepos, making them vulnerable targets.
* Epicenter and Sand Storm's AoE damage ensures all Meepo clones get damaged, making it hard for Meepo to choose which one to flee as all are taking damage at the same rate.
* Just be aware when using Sand Storm to escape, as Meepo has good AoE damage and disables, which, as explained in the "Bad Against" section, works well against an invisible Sand King.
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.
Sand King
* Burrowstrike can be used as an escape or initiation against Broodmother.
* Sand Storm quickly kills any spiderlings caught inside if Sand King can manage to stun them.
Additional:
* Caustic Finale allows Sand King to easily kill Broodmother's Spiderlings throughout the game.
* Sand King can usually catch a split pushing Broodmother with Blink Dagger and Burrowstrike.
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.
Sand King
* 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.
Sand King
* Slark will have a hard time killing Sand King because of the survivability he gets from Burrowstrike and Sand Storm.
* 
Shadow Dance, which usually allows Slark to survive fights, is ineffective against Sand King's AoE damage.
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.
Sand King
* 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.
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.
Sand King
* Sand King is a strong ganker, allowing him to shut down squishy heroes in the early game: Phantom Assassin, Clinkz, Sniper, Enchantress.
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.
Sand King
* Heroes that rely on slows to get kills: Lifestealer, Night Stalker, Ursa, Phantom Assassin, Terrorblade.
Mars
* Heroes that are hard to gank: Dragon Knight, Mars, 
Centaur Warrunner.
Sand King
* Burrowstrike, Sand Storm, Caustic Finale and Epicenter will deal a large amount of damage to Chen and his creeps.
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.
Sand King
* Sand King can quickly remove her 
Refraction with his Sand Storm.
* Once Refraction is down, she is very vulnerable to Epicenter's high magic damage.
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.
Sand King
* Sand King's massive area damage output, particularly Epicenter, allows him to quickly take down Chaos Knight and his illusions.
* Sand King can also apply Caustic Finale to illusions with attacks for extra damage when they die.
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
* 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.
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.
Sand King
* Sand King's Sand Storm damages familiars quickly whittling them down in health, rendering them vulnerable.
* Sand King's Epicenter quickly damages and destroys familiars.
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.
Mars
* Heroes who can disable Mars but cannot do any damage to him, meaning he just tanks their abilities: 
Doom, Magnus.
Sand King
* Sand King is a strong ganker, allowing him to shut down squishy heroes in the early game: Phantom Assassin, Clinkz, Sniper, Enchantress.
Sand King
* Since Naga Siren is a hero who barely goes for Black King Bar, she is vulnerable to nukers with strong magical damage and big area-of-effect spells in every game more than any other carry heroes: Sand King, Jakiro, 
Leshrac, Lina, Earthshaker, Zeus.
Mars
* Heroes that can negate Hoodwink's mobility: Kunkka, Disruptor, Mars.
Sand King
* Heroes with no mobility will take some good damage from Sand King's spells: Dragon Knight, Jakiro, Pugna, Earthshaker.
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.
Sand King
* Heroes with no mobility will take some good damage from Sand King's spells: Dragon Knight, Jakiro, Pugna, Earthshaker.
Sand King
* 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
* Durable heroes: Axe, Dawnbreaker, Bristleback, Mars, Omniknight, Tidehunter, Wraith King, 
Primal Beast, Underlord.
Mars
* Heroes that are hard to gank: Axe, Death Prophet, Phantom Lancer, 
Slark, Centaur Warrunner, Bristleback, Medusa, Mars.
Sand King
* Heroes with no mobility will take some good damage from Sand King's spells: Dragon Knight, Jakiro, Pugna, Earthshaker.
Mars
* Heroes who lack burst damage will have a hard time against Mars: Phantom Lancer, Nature's Prophet, Lich.
Mars
* Heroes who rely on their target to run away: Riki, Bounty Hunter.
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
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
* 
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.
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
* 
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.
Sand King
* 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
* 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.
Sand King
* Heroes that rely on slows to get kills: Lifestealer, Night Stalker, Ursa, Phantom Assassin, Terrorblade.
Sand King
*
Zeus usually stays at the back in teamfights and it is hard for Sand King to find Zeus and knock him down before Zeus deals his damage.
Thundergod's Wrath, disables Sand King's 
Blink Dagger, effectively reducing Sand King's initiation and counter-initiation potential.
Lightning Bolt deals damage to Sand King in Sand Storm and reveals him. It also interrupts channeling of Epicenter.
* All of Zeus' abilities, especially
*
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.