Medusa
* 
Burning Spear's damage over time can rapidly burn Medusa's mana and health alike.
* 
Inner Fire can slow and disarm Medusa and also allow Huskar to follow up with Life Break.
Monkey King
* Burning Spears can put 
Monkey King's 
Tree Dance on cooldown.
Medusa
* Fiend's Grip provides mana drain, which can heavily damage 
Mana Shield and prevent Medusa from using 
Stone Gaze.
* Even if she does use Stone Gaze, Nightmare can buy enough time to protect allies and reset the fight.
Additional:
* 
Fiend's Grip leaves Medusa defenseless, since not only does it deal damage, it also drains mana.
Monkey King
* Low-health, normally mobile carries who rely entirely on raw attack damage are vulnerable to Bane's nukes and disables: 
Anti-Mage, 
Clinkz, 
Drow Ranger, 
Faceless Void, 
Gyrocopter, 
Juggernaut, 
Meepo, 
Mirana, Monkey King, 
Morphling, 
Phantom Assassin, 
Phantom Lancer, 
Riki, 
Shadow Fiend, 
Slark, 
Sniper, 
Terrorblade, 
Troll Warlord, 
Weaver.
Medusa
* E.M.P. allows Invoker to burn Medusa's mana to weaken Mana Shield.
* Medusa's lack of mobility makes her easy to kite with Invoker's spells.
Additional:
* 
E.M.P. is a large mana burn nuke which can hit Medusa's Mana shield with enough damage to lose even more mana.
* 
Deafening Blast disarms Medusa's ability to deal pseudo-AOE damage during teamfights.
* 
Cold Snap allows the opposing team to repeatedly stun Medusa in short succession, preventing her from successfully casting her ultimate due to its long cast time.
Monkey King
* Heroes with long animations can be frequently interrupted with Cold Snap: 
Earthshaker, Monkey King, Shadow Fiend 
Lina
Medusa
* Medusa is especially vulnerable to 
Essence Shift, as both strength and intelligence contribute to her effective HP, while agility contributes to her damage.
* 
Dark Pact when timed right can be used to dispel Stone Gaze right after it petrifies Slark, allowing him to keep attacking Medusa throughout the duration.
Additional:
* Medusa cannot chase Slark in any way and has no disable beyond her ultimate, making her unable to stop him getting away and regenerating before coming back to finish her off.
* Essence Shift particularly removes 1 intelligence point per hit, thus lowering Medusa's mana pool's cap and leaving her much more vulnerable in prolonged fights.
Monkey 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.
Medusa
* Heroes with extremely slow movement speed will cripple against Solar Bind: 
Medusa, 
Viper
Additional:
* 
Will-O-Wisp will keep Medusa busy after she got hit by 
Blinding Light.
Monkey King
* Blinding Light can knock Monkey King outside of his ultimate, Wukong's Command and can blind him.
* Will-O-Wisp will stun Monkey King from Tree Dance by destroying his tree.
Additional:
* Blinding Light can easily push Monkey King out of Wukong's Command, as well as blinding him.
* Monkey King is vulnerable to burst damage, 
Solar Bind makes him more so
* However, Keeper of the Light can be easily ganked by Monkey King during early-mid game stage.
Medusa
* With 
Static Link, Razor can effectively make Medusa useless in teamfights by reducing her main damage output. It can, however, be blocked by a 
Linken's Sphere.
* 
Plasma Field allows Razor to get on top of Medusa, slowing her already slow movement speed to a mere crawl.
* 
Eye of the Storm capitilizes on Medusa's low armor and causes her to be very vulnerable, even through Mana Shield.
Monkey King
* Heroes with wide AoE abilities will reveal Monkey King through Mischief: 
Necrophos, Phoenix, 
Alchemist, Earthshaker, 
Razor, 
Tinker, 
Leshrac, Queen of Pain
Additional:
* Static Link can steal the bonus damage from 
Jingu Mastery and reduce the physical damage from 
Boundless Strike. It also reduces 
Wukong's Command's damage if it's used after stealing damage via Static Link.
* Static Link will give Razor shared vision on Monkey King if he tries to escape using Tree Dance or 
Mischief.
* Plasma Field can prevent Monkey King from using Tree Dance and Mischief.
* Eye of the Storm will remove the armor buff from Wukong's Command, as well as hitting Monkey King during Mischief.
Medusa
* Heroes who take a long time to become strong are in for a rough mid game, such as 
Outworld Destroyer, Magnus, Medusa, and Anti-Mage.
Monkey King
* Keeping Void Spirit inside Wukong's Command is a very tricky task, especially in the early and mid game. In addition, if Monkey King is in a bad position, a well placed Aether Remnant can easily pull him out of the ring.
* Getting stacks of Jingu Mastery can be difficult when attacking Void Spirit.
Medusa
* Sniper can outrange both Medusa's arrows and Stone Gaze, allowing him to focus her down during a teamfight.
Additional:
* Medusa is a fairly immobile hero that deals damage around her with 
Split Shot. Sniper should outrange her and should stay out of harm's way from Split Shot.
* More importantly, Sniper should have enough attack range to fire at Medusa during her Stone Gaze without turning to stone, so the ultimate is mostly wasted against him.
Monkey King
* Heroes that can maintain vision on Monkey King can see when he uses Tree Dance: 
Bloodseeker, 
Treant Protector with Eyes In The Forest, Sniper, Weaver
Medusa
* 
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.
Monkey King
* 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.
Medusa
* Medusa's Stone Gaze forces Mars to choose between getting petrified, or turning his vulnerable back on Medusa.
Monkey King
* Power Cogs pushes Monkey King out of Wukong's Command, ending his ultimate.
* Rocket Flare allows Clockwerk to scout Monkey King in the trees, and chase him with Hookshot.
Monkey King
* 
Wave of Terror grants flying vision over trees, and its wide effect can hit Monkey King and end Mischief.
* 
Nether Swap can easily cancel Wukong's Command by swapping him out of the circle.
Additional:
* She can easily cancel Wukong's Command with Nether Swap.
* Wave of Terror can also detect him while he's on the trees.
Monkey King
* 
Thunder Strike provides vision of Monkey King when he's in the trees. The periodic damage will also keep Monkey King from using Tree Dance if he's on the ground.
* 
Glimpse pulls Monkey King out of the trees if he attempts to escape using Tree Dance, and can cause Wukong's Command to end prematurely if Monkey King is Glimpsed out of its radius.
* However, if Monkey King strikes first, if he has already casted Wukong's Command, Disruptor's abilities will not be much of an use
Medusa
* Ursa's status resistance from 
Enrage reduces duration of Medusa's Stone Gaze.
* Ursa can stack damage with 
Fury Swipes easily against her Mana Shield in a prolonged team match.
Additional:
* Medusa's tankiness doesn't help her very much against Fury Swipes in long teamfights.
* With no escape mechanism and a slow movement speed, getting jumped on by Ursa usually spells a quick end for Medusa in the early game.
Monkey King
* 
Icarus Dive and 
Supernova can destroy the tree Monkey King is standing on.
* 
Fire Spirits reduces Monkey King's attack speed, preventing Monkey King from building up Jingu Mastery.
* Supernova can be casted next to Wukong's Command, forcing Monkey King to step away of it or to withstand its massive AOE damage
Additional:
* Icarus Dive, Sun Ray, and Supernova all destroy trees that Monkey King relies on to use his ability Tree Dance. If you spot him, you can quickly Icarus Dive in his direction and then follow up with Fire Spirits and Supernova. If you manage to cut the tree he is on, he will be stunned for 4 seconds and will be forced to take a lot of damage. However, most Monkey King players tend to build attack speed items to make use of their passive, Jingu Mastery, so a battle against a farmed Monkey King will depend on who gets the jump on the other first.
Medusa
* 
Vendetta burns a significant amount of mana on hit, and the damage from the ability drains Medusa's mana pool even further.
* Due to the passive nature of Mystic Snake and Split Shot, it can possibly proc Nyx's 
Spiked Carapace if he's within range of Medusa's abilities and isn't invisible.
* Medusa lacks single target damage, making Nyx with 
Aghanim's Scepter extremely hard to deal with if Medusa is the team's main damage source.
Additional:
* With her passive Split Shot, Medusa can be easily interrupted by Spiked Carapace during combat, especially during her precious Stone Gaze.
* Mana Burn quickly destroys Mana Shield, especially if Medusa only increases her mana pool by bolstering intelligence (which has the added bonus of increasing Mana Burn's damage).
* Uncontrollable damage from 
Mystic Snake and Split Shot can trigger Spiked Carapace.
* Medusa lacks single target damage, making a Burrowed Nyx Assassin hard to kill.
Medusa
* Anti-Mage easily destroys Mana Shield with Mana Break, especially once he has 
Manta Style.
* Anti-Mage effectively avoids Stone Gaze with Blink, and can reinitiate after its duration is over.
Additional:
* 
Mana Break burns Medusa's mana easily, especially when coupled with a Manta Style.
* Can easily initiate on Medusa with 
Blink, burning her mana or forcing her to use Stone Gaze.
* 
Mana Void is effective against Medusa's big mana pool and mana usage, presenting a huge hazard to Medusa's allies around her since her Mana Shield still gives her some protection if she has mana.
Medusa
* With 
Smoke Screen, Riki will silence and catch Medusa in a surprise with high miss chance flushing her from positions easily in team fights.
* He can deal a huge amount of damage through 
Cloak and Dagger, even through Mana Shield.
Monkey King
* Heroes with blind of some sort can be a bad choice for Monkey King to go on: 
Broodmother, Riki, 
Keeper of the Light.
Monkey King
* In general, heroes who are melee with no way to fight back can be very easily poked by Monkey King to gain his Jingu Mastery stacks: 
Dark Seer, Riki, 
Rubick.
Monkey King
* 
Blink allows Queen of Pain to avoid ganks and keep her distance, preventing Monkey King from building up Jingu Mastery.
* 
Scream of Pain and 
Sonic Wave will hit Monkey King when he is disguised, or on a tree.
* The large AoE and low cooldown also helps Queen of Pain hit the real Monkey King inside of Wukong's Command.
Medusa
* Medusa lacks mobility or escape mechanisms. 
Earth Spike and 
Hex can neutralize her strong damage potential and allow for 
Lion's team to focus her down.
* 
Mana Drain is a perfect ability to weaken Medusa's durability as it can quickly drain her Mana Shield, making her far less tanky. Mana Drain can also be used to restore mana of Lion's allies, which can nullify the mana steal from Mystic Snake.
* Mana Drain, along with Hex, destroy illusions instantly, which may be extremely helpfull and efficient against core builders of Manta Style, like Medusa herself.
Monkey King
* Terrorize forces Monkey King out of Wukong's Command.
Monkey King
* 
Nethertoxin prevents the buildup of Jingu Mastery stacks.
* Viper's poison magical damage-over-time stops Monkey King from using Tree Dance. It also ignores the extra armor bestowed by Wukong's Command.
Additional:
* 
Viper STrike prevents the buildup of Jingu Mastery stacks.
* Monkey King's high base movement speed is of little worth against the array of slows Viper possesses.
* All of Viper's magical damage over time stops Monkey King from using Tree Dance. It also ignores the extra armor bestowed by Wukong's Command.
Monkey King
* 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.
Monkey King
* 
Ball Lightning allows Storm Spirit to easily catch up to Monkey King, destroying a large number of trees, cancelling Tree Dance, and causing Monkey King to be stunned in the process.
Additional:
* Ball Lightning allows Storm Spirit to destroy a large amount of trees, negating Tree Dance. It also makes it easy to avoid Wukong's Command and Boundless Strike.
Monkey King
* 
Cinder Brew and 
Drunken Brawler makes it hard for Monkey King to stack Jingu Mastery.
* 
Cyclone can remove Monkey king for 6 seconds if his allies lack dispels.
* 
Dispel Magic can dispel Jingu Mastery's bonuses.
Medusa
* He can use either his own or his double's 
Flux to bypass the spellblock from Linken's Sphere, using the leftover Flux + 
Spark Wraith to slow Medusa's already low move speed to a crawl.
* Arc Warden has a farming advantage with double 
Hand of Midas, and can generally bully Medusa with other items that benefit from duplication.
Monkey King
* Firefly destroys trees and can turn Tree Dance into a free four second stun.
Additional:
* 
Firefly allows Batrider to gain vision of Monkey King while he is on an tree, as well as destroying any nearby trees, denying Monkey King spots to jump to, or causing him to fall.
* 
Sticky Napalm's turn rate slow makes it significantly more difficult for Monkey King to jump from tree to tree and gain Jingu Mastery stacks. It also reveals Monkey King while he is on a tree.
* 
Flamebreak and 
Flaming Lasso enable Batrider to remove Monkey King out of Wukong's Command.
Monkey King
* Timbersaw's low cooldown and low mana cost abilities destroys the trees that Monkey King depends on.
* 
Timber Chain allows Timbersaw to escape Wukong's Command.
Additional:
* Timbersaw can easily cut down the tree that Monkey King is standing on, stunning him for a lengthy period.
* Timbersaw can use Timber Chain to easily escape Wukong's Command and 
Primal Spring's slow.
* However, when facing Monkey King mid, Timbersaw might get harassed out of the lane because of Jingu Mastery.
Monkey King
* Monkey King often hides in trees, where he can be easily caught with 
Bushwhack.
* 
Acorn Shot can target enemies in the fog, including Monkey King when he is on a tree.
* 
Sharpshooter provides flying vision along the cast indicator while charging, which can be used to scout the trees for Monkey King.
Monkey King
* 
Powershot destroys the tree Monkey King is standing on.
* Monkey King's natural reliance on trees makes him an easy target for 
Shackleshot.
* 
Windrun evades Monkey King's attacks, preventing him from building up Jingu Mastery.
Monkey King
* 
Proximity Mines can be placed near trees to detect Monkey King.
* Follow up with 
Blast Off! to destroy the tree, causing Monkey King to take high damage, fall from the tree, and become stunned.
Additional:
* Techies can turn his tree jumping ability against him, by placing Proximity Mines that will detect him near trees, and then destroying the trees around him with Blast Off, stunning him and dealing high damage, on top of him being silenced when the stun expires.
* Monkey King's mobility is also severely limited around Techies' mines as he will almost always trigger them due to the cooldown time between tree jumps. Monkey King will be forced to take mine damage or escape with Primal Spring.
Medusa
* Phantom Lancer with 
Diffusal Blade will very quickly burn Medusa's mana, making Mana Shield significantly less effective.
* 
Doppelganger's 1 second invulnerability can be used to dodge Medusa's petrification from Stone Gaze, as well as Mystic Snake.
* Phantom Lancer's illusions outnumber Medusa's targets from Split Shot, likely shielding his team in the process.
Monkey King
* Heroes that can destroy trees will deny Monkey King spots to jump on, or cause him to fall: 
Windranger, 
Nature's Prophet, Phantom Lancer
Monkey King
* Monkey King's Jingu Mastery is undispellable and puts a big yellow Mark over his head.
* Heroes with undispellable debuffs will help identify the real Phantom Lancer through visual effects or debuff indicators, provided that it was cast on the real Phantom Lancer to begin with:
* 
Doom's 
Doom marks Phantom Lancer with a highly visible effect, and also silences and mutes him.
* Bloodseeker's 
Rupture shows a clear red trail effect on the real Phantom Lancer.
* 
Ancient Apparition's 
Ice Blast will only debuff Phantom Lancer and not his illusions.
* 
Grimstroke's 
Soulbind is undispellable.
* 
Shadow Demon's 
Demonic Purge is undispellable.
* Monkey King's Jingu Mastery is undispellable and puts a big yellow Mark over his head.
Medusa
* Other heroes who has armor and slow debuffs won't allow Medusa to disengage from combat: 
Tidehunter, 
Bristleback, 
Slardar.
Medusa
* Heroes that build Diffusal Blade or can fit it well into their item build will also make Medusa much less tanky: Riki, 
Naga Siren, Terrorblade, Juggernaut, 
Spectre, Slark.
Monkey King
* Heroes with wide AoE abilities will reveal Monkey King through Mischief: Necrophos, Phoenix, Alchemist, Earthshaker, Razor, Tinker, Leshrac, Queen of Pain
Monkey King
* Monkey King is also hindered by Track since he relies on trees to hide him from vision.
Additional:
* 
Track grants vision of Monkey King, even when he's in the trees.
Monkey King
* Heroes with wide AoE abilities will reveal Monkey King through Mischief: Necrophos, Phoenix, Alchemist, Earthshaker, Razor, Tinker, Leshrac, Queen of Pain
Monkey King
* Heroes with wide AoE abilities will reveal Monkey King through Mischief: Necrophos, Phoenix, Alchemist, Earthshaker, Razor, Tinker, Leshrac, Queen of Pain
Medusa
* Axe can take advantage of Medusa's awfully low HP to insta-kill her with 
Culling Blade, making it extremely difficult for her to farm for items to compensate for the lack of strength during early and mid-game while Axe is continuously harassing around.
Monkey King
* Heroes that can keep Monkey King stunned for a long time can pose a threat: 
Axe, 
Centaur Warrunner.
Medusa
* Mana Shield reduces the effectiveness of Counter Helix.
* Stone Gaze makes it very difficult for Axe to initiate on Medusa and her allies.
Monkey King
* Heroes that can keep Monkey King stunned for a long time can pose a threat: Axe, Centaur Warrunner.
Medusa
* Heroes that build Diffusal Blade or can fit it well into their item build will also make Medusa much less tanky: Riki, Naga Siren, Terrorblade, Juggernaut, Spectre, Slark.
Monkey King
* Tusk can 
Walrus Kick Monkey King out of Wukong's Command.
Additional:
* Tusk can Walrus Kick Monkey King from Wukong's Command, making his ultimate useless.
Medusa
* Other heroes who has armor and slow debuffs won't allow Medusa to disengage from combat: Tidehunter, Bristleback, Slardar.
Monkey King
* 
Skewer and 
Reverse Polarity will often push Monkey King out of Wukong's Command.
Medusa
* 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.
Monkey King
* The Hawk can easily find Monkey King while he is sitting on a tree.
* Wild Axes can knock out Monkey King from tree.
* Boars drastically reduce Monkey King's attack speed, making it harder for him to gain Jingu Mastery stacks.
Additional:
* 
Wild Axes can chop down trees, making it difficult for Monkey King to utilize Tree Dance well.
* 
Call of the Wild Hawk can scout Monkey King when he is perched on top of trees.
* 
Primal Roar can stun Monkey King for a lengthy duration even with spell immunity.
Medusa
* Heroes with Linken's Sphere as core item: Weaver, Morphling, Medusa.
Monkey King
* 
Blur makes it hard for Monkey King to stack Jingu Mastery.
* 
Phantom Strike allows Phantom Assassin to blink directly to Monkey King during Wukong's Command, bypassing all his clones.
* 
Coup de Grace's high damage can kill Monkey King quickly, thus ending Wukong's Command prematurely.
Medusa
* Heroes with disables that ignore spell immunity will render Phantom Assassin completely useless in teamfights throughout the game: Axe, Enigma, 
Vengeful Spirit, Doom, 
Bane, 
Beastmaster, 
Pudge, Medusa, 
Warlock.
Medusa
* Medusa's Split Shot can easily kill Chen's creeps.
* Mystic Snake can quickly kill Chen's creeps and deal intense damage for every killed creep while also draining their mana with each bounce. Aghanim's Scepter upgraded Mystic Snake can also disable both, Chen and his creeps upon impact.
* Mana Shield will make it impossible for Chen to burst down Medusa.
* Stone Gaze can disable Chen from using 
Hand of God to save himself or his allies.
Monkey King
* Monkey King can kill Chen or any of his allies with his physical damage burst from Boundless Strike and Jingu Mastery before he can use Hand of God.
* None of the neutral creeps have any abilities to destroy trees, which makes Chen an excellent target for ganks with Tree Dance and Primal Spring.
Medusa
* Poof won't damage Medusa and she can use Stone Gaze to disable all of Meepo's clones.
* Mystic Snake will easily become the bane of Meepo early game.
Monkey King
* Tree Dance and Primal Spring allows him to chase a retreating Meepo.
* Boundless Strike gains critical strike bonuses and Wukong's Command can take down Meepo and his clones very quickly.
Additional:
* Monkey King can gain Jingu Mastery stacks on Meepo’s clones from 
Divided We Stand.
* Tree Dance allows him to sneak up on and gank a lone Meepo clone.
Medusa
* 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.
Monkey King
* 
Firestorm will do little percentage damage to a small HP hero like Monkey King.
* All aspects of Jingu Mastery benefits ignore 
Atrophy Aura's base damage reduction.
* Monkey King can get on top of Underlord easily at any stage of the game.
Medusa
* Mana Shield makes Medusa very hard to take down in Duels.
* Stone Gaze stops Legion Commander from Dueling altogether, regardless of who she targets.
Monkey King
* 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
Medusa
* Lifestealer's low mobility makes him easy to kite.
* Stone Gaze pierces 
Rage, wasting its cooldown and making Lifestealer unable to fight.
Monkey King
* 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
Medusa
* Doom does not disable Mana Shield. As such, Doom's damage is largely mitigated by her mana shield. Additionally, Medusa is not reliant on her abilities to be effective during a teamfight, making Medusa an unproductive hero to target.
* Medusa is an ideal Linken's Sphere carrier. Should one be purchased, and without any additional disables, Doom may find that few opportunities exist to effectively lockdown, disable, and kill Medusa.
Medusa
* 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
* Split Shot will keep attacking Pangolier even when he is rolling around.
* Stone Gaze stuns Pangolier during Rolling Thunder, or forces him to roll away.
Monkey King
* Wukong's Command and Boundless Strike combo can easily cause havoc on Chaos Knight by destroying all of his powerful illusions.
* Chaos Knight without Phantasm cannot deal with Jingu Mastery at all.
Monkey King
* His low armor deters him from a trade,while Jingu Mastery allows Monkey King to retaliate.
* Buffed Boundless Strike heals Monkey King and can potentially execute Pudge.
* Monkey King can scout Pudge's positioning from the trees, making it easier for him and his allies to dodge 
Meat Hook.
* With a better-than-average strength gain, he usually survives Pudge's combo.
Monkey King
* Skywrath Mage's very low health allows Monkey King to ambush and finish him off quickly.
Monkey King
* Requiem of Souls is easily interrupted by Boundless Strike, due to its long cast time.
* Shadow Fiend's lack of mobility and escape makes him an easy target to ambush with Primal Spring, especially during laning stage.
* Being close means he cannot use all three razes on you before you get your Jingu Mastery stacks.
Medusa
* If Medusa activates Stone Gaze before Spirit Breaker reaches her with Charge of Darkness, the charge will inevitably fail.
* Medusa has three ways to counter Spirit Breaker's Charge of Darkness: Stone Gaze can disable Spirit Breaker's Charge of Darkness if he faces Medusa directly. Aghanim's Scepter upgraded Mystic Snake can disable Spirit Breaker and cancel his Charge of Darkness if it hits him. And 
Cold Blooded provided by Aghanim's Shard that can cast a single-targeted Mystic Snake at Spirit Breaker if he uses Charge of Darkness on her.
* Mana Shield and overall tankiness allows Medusa to easily survive Spirit Breaker's initiation. And to make things worse, Spirit Breaker is not a common Diffusal Blade nor 
Disperser wielder to counter this problem at all.
* Overall, any attempt for Spirit Breaker to gank and kill Medusa will hurt him more than the other way around.
Medusa
* Stone Gaze allows Medusa to easily kite and kill Sven.
* Mana Shield negates much of Sven's burst damage.
Additional:
* Mana Shield makes it very hard for Sven to burst her within Storm Hammer's stun duration.
* Stone Gaze makes it very difficult for Sven to fight Medusa at any stage of the game.
* Mystic Snake can slow Sven down enough for allies to capitalize on his commitment in a fight.
Monkey King
* Monkey King’s clones from Wukong’s Command and Aghanim’s Scepter are immune to Chronosphere, so it is a very bad idea to Chronosphere Monkey King with his clones around.
Additional:
* Monkey King’s clones from Wukong’s Command and Aghanim’s Scepter are immune to Chronosphere, so it is a very bad idea to Chronosphere Monkey King with his clones around.
* If Monkey King's himself is not caught inside Chronosphere, he can cast Wukong Command's next to it to force Faceless Void to scatter
Monkey King
* Monkey King can scout Drow Ranger's positioning from the trees, and can jump on her without much trouble, disabling 
Marksmanship
* She lacks innate mobility to escape from Wukong's Command, whose bonus armor gives MK one extra edge in the fight
Monkey King
* Jingu Mastery will still add stacks even through 
Guardian Angel.
* Monkey King can join a fight whenever he chooses to, meaning he can simply go directly onto Omniknight.
* During the laning phase, Jingu Mastery with Boundless Strike will kill off Omniknight, while 
Purification is weak.
* 
Heavenly Grace is useless against Monkey King's ultimate and Jingu Mastery bonuses.
Medusa
* Split Shot can destroy Tombstone Zombies and Tombstone itself while still damaging heroes.
Medusa
* Visage's familiars are easy targets to Split Shot.
* Mana Shield will resist Soul Assumption instances without effort.
Medusa
* Heroes with a lot of burst damage, especially those who rely on casting spells: Lina, Zeus.
Medusa
* Any long duration disables that can pierce through both, Pierce The Veil and 
Black King Bar are devastating against Muerta: Enigma's Black Hole, Dawnbreaker's Solar Guardian, Axe's Berserker's Call, Naga Siren's Aghanim's Scepter upgraded 
Ensnare and 
Reel In from Aghanim's Scepter, Jakiro's Aghanim's Scepter upgraded Macropyre, Bane's Fiend's Grip, Pudge's 
Dismember, Batrider's Flaming Lasso, Beastmaster's Primal Roar, Grimstroke's Soulbind, Medusa's Stone Gaze, Magnus's Reverse Polarity.
Monkey King
* In general, heroes who are melee with no way to fight back can be very easily poked by Monkey King to gain his Jingu Mastery stacks: Dark Seer, Riki, Rubick.
Monkey King
* 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
Additional:
* Wraith King has no ability to destroy trees from Tree Dance.
* Monkey King tends to get Diffusal Blade, leaving Wraith King no mana to reincarnate unless Wraith King has his Aghanim's Shard.
* A reincarnated Wraith King is an ideal target for Wukong's Command.
Medusa
* Heroes that are hard to gank: Axe, Death Prophet, Phantom Lancer, Slark, Centaur Warrunner, Bristleback, Medusa, Mars.
Monkey King
* In general, heroes who are melee with no way to fight back can be very easily poked by Monkey King to gain his Jingu Mastery stacks: Dark Seer, Riki, Rubick.
Monkey King
* Heroes with stronger lane presence that can threaten to kill him: Batrider, Juggernaut, 
Ursa, Monkey King, Razor.
Medusa
* Heroes that build Diffusal Blade or can fit it well into their item build will also make Medusa much less tanky: Riki, Naga Siren, Terrorblade, Juggernaut, Spectre, Slark.
Medusa
* Medusa's Split Shot and Mystic Snake combined with 
Mjollnir, a common item for Medusa, will whittle down all of Naga Siren's illusions, including Naga Siren herself.
* Medusa's Stone Gaze can disable Naga Siren even for the duration of Song of the Siren and even if Naga Siren is spell immune, discouraging Naga Siren from even trying to use Song of the Siren to save herself or counter-initiate against Medusa.
Additional:
* Medusa's Split Shot and Mystic Snake combined with Mjollnir, a common item for Medusa, will whittle down all of Naga Siren's illusions, including Naga Siren herself.
* Medusa's Stone Gaze can disable Naga Siren even for the duration of Song of the Siren and even if Naga Siren is spell immune, discouraging Naga Siren from even trying to use Song of the Siren to save herself or counter-initiate against Medusa.
Monkey King
* Heroes who are melee but cannot fight back against Eclipse will really struggle with Luna: Monkey King, Alchemist, Timbersaw.
Medusa
* Should Luna choose to buy Manta Style, Medusa will be able to kill illusions from them with Split Shot and Mjollnir, which is a common item on Medusa.
* Mystic Snake allows Medusa to easily harass Luna and steal mana from her, preventing Luna from retaliating with 
Lucent Beam.
* Medusa can survive Eclipse thanks to Mana Shield, which can cause Luna to struggle greatly in bursting down Medusa and force her to buy Diffusal Blade and it's upgrade Disperser.
* Even with Black King Bar, Medusa's Stone Gaze will still be able to disable Luna, which could even discourage her from counter-initiating with Eclipse.
Additional:
* Should Luna choose to buy Manta Style, Medusa will be able to kill illusions from them with Split Shot and Mjollnir, which is a common item on Medusa.
* Mystic Snake allows Medusa to easily harass Luna and steal mana from her, preventing Luna from retaliating with Lucent Beam.
* Medusa can survive Eclipse thanks to Mana Shield, and since Luna is not a hero that often goes for Diffusal Blade, she will struggle greatly in bursting down Medusa.
* Even with Black King Bar, Medusa's Stone Gaze will still be able to disable Luna, which could even discourage her from counter-initiating with Eclipse.
* For the same reasons, Medusa makes a very powerful ally for Luna when they are in the same team.
Monkey King
* Heroes that can maintain vision on Monkey King can see when he uses Tree Dance: Bloodseeker, Treant Protector with Eyes In The Forest, Sniper, Weaver
Monkey King
* Monkey King is one of the few other heroes who can easily traverse through trees, counteracting Treant Protector's ability to hide in trees.
Medusa
* Heroes that build Diffusal Blade or can fit it well into their item build will also make Medusa much less tanky: Riki, Naga Siren, Terrorblade, Juggernaut, Spectre, Slark.
Monkey King
* 
Dispersion will not do anything against throughout the game due to his high lifesteal with Jingu Mastery.
* Monkey King often buys Manta Style, which will deny 
Desolate benefits in 1v1 situations.
* 
Haunt will do nothing to stop people trapped within Monkey Kings ultimate.
* In all, Spectre is very easily pressured by Monkey King early into the game and is a very easy gank target to coordinate with your team.
Monkey King
* Heroes with wide AoE abilities will reveal Monkey King through Mischief: Necrophos, Phoenix, Alchemist, Earthshaker, Razor, Tinker, Leshrac, Queen of Pain
Medusa
* Mana Shield can tank most of the damage from Reaper's Scythe; with sufficient mana, the kill threshold drops significantly.
* Necrophos has a movement speed equal to Medusa, and is easy to chase down with a slowing item in Medusa's inventory.
Monkey King
* Heroes that can destroy trees will deny Monkey King spots to jump on, or cause him to fall: Windranger, Nature's Prophet, Phantom Lancer
Additional:
* Nature's Prophet's Natures's Call can destroy trees while Monkey King is standing on them with Tree Dance, which will stun him for a good deal of time.
Monkey King
* 
Sprout will not protect Nature's Prophet from Tree Dance.
* Boundless Strike will interrupt attempts at 
Teleportation, and can reach Nature's Prophet inside the tree line.
Monkey King
* Heroes with wide AoE abilities will reveal Monkey King through Mischief: Necrophos, Phoenix, Alchemist, Earthshaker, Razor, Tinker, Leshrac, Queen of Pain
Monkey King
* Alchemist has very bad armor and does not build armor items for the large majority of his build, so Jingu Mastery and Wukong's Command can be very deadly.
* 
Desolator, 
Sange and Yasha or Diffusal Blade can all be purchased to increase your damage against Alchemist or just to keep your movement speed high enough to match him while 
Chemical Rage is active.
* Monkey King is an agility hero and scales with armor, so Acid Spray loses it's effectiveness later in the game.
Monkey King
* Heroes that can maintain vision on Monkey King can see when he uses Tree Dance: Bloodseeker, Treant Protector with Eyes In The Forest, Sniper, Weaver
Medusa
* Mana Shield makes it very difficult for Bloodseeker to gain his Thirst bonuses.
* Rupture rarely kills Medusa through Mana Shield.
Monkey King
* 
Impetus pure damage ignores the extra armor granted from Wukong's Command.
* 
Enchant can dispel Monkey King's Jingu Mastery bonuses.
* 
Untouchable makes it hard for Monkey King to land Jingu Mastery stacks.
* 
Sproink allows Enchantress to escape from Wukong's Command.
Medusa
* Enchantress often has a small army of neutral creeps, allowing Medusa to hit her with a later bounce of her Mystic Snake.
Monkey King
* Another hero that should not leave a special circle for his ultimate. The only thing to be afraid is Boundless Strike.
Monkey King
* 
Paralyzing Cask's short stun rarely prevents Monkey King from ambushing Witch Doctor.
* 
Death Ward's long channel is easily interrupted by Boundless Strike.
Medusa
* Other heroes who has armor and slow debuffs won't allow Medusa to disengage from combat: Tidehunter, Bristleback, Slardar.
Medusa
* Medusa cares less than other heroes about armor reduction, since Mana Shield blocks 70% of all damage without taking armor/magic resistance into consideration. This makes 60% of your Corrosive Haze ineffective until Medusa's mana is drained.
Monkey King
* Heroes that can maintain vision on Monkey King can see when he uses Tree Dance: Bloodseeker, Treant Protector with Eyes In The Forest, Sniper, Weaver
Monkey King
* 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
Monkey King
* Zeus is good against heroes that juke in trees or up cliffs, like Batrider, Monkey King, Spectre, and Tinker, by providing vision in any area with Lightning Bolt, or guaranteeing vision on enemies with Thundergod's Wrath.
Medusa
* Heroes with a lot of burst damage, especially those who rely on casting spells: Lina, Zeus.
Monkey King
* Malefice will cause Monkey King to struggle without Black King Bar, as its periodic damage and stun disables/interrupts abilities, such as Tree Dance and Wukong's Command.
* Midnight Pulse can also destroy trees in a wide radius, stunning Monkey King if he happened to be on a tree caught within Midnight Pulse area-of-effect.
Additional:
* 
Malefice keeps Tree Dance on cooldown, and can interrupt Wukong's Command's long cast time.
* Midnight Pulse destroys a large amount of trees.
Medusa
* Medusa's Split Shot can make quick work of Enigma's Eidolons and take advantage of their considerable bounty.
* Medusa can also kill Eidolons with her Mystic Snake that can also greatly damage Enigma and drain some of his mana.
* If Medusa activates Stone Gaze at the start of a fight, it can make initiating and landing an effective Black Hole exceedingly difficult, because Stone Gaze can cancel Enigma's Black Hole even through spell immunity, which can discourage Enigma from even trying to initiate with Black Hole.
Additional:
* Medusa's Split Shot can make quick work of Enigma's Eidolons and take advantage of their considerable bounty.
* If Medusa activates Stone Gaze at the start of a fight, it can make initiating — and landing an effective Black Hole exceedingly difficult. Stone Gaze can cancel Enigma's Black Hole even through spell immunity, which can discourage Enigma from initiating with Black Hole.
Medusa
* Silencer burns easily through her effective HP from Mana Shield, by taking away her intelligence.
* 
Arcane Curse punishes her repeatedly casting Mystic Snake to keep her mana pool high. He can force her to use Manta Style before he has cast 
Global Silence and Medusa usually does not want to build Black King Bar.
Monkey King
* Silencer's low mobility and lack of any stuns or roots makes him an easy target.
* Silence will not protect Silencer from Jingu Mastery's extra damage and lifesteal.
* Monkey King often buys Black King Bar, which can be used to negate silence debuff effects.
Medusa
* Webbed areas can be used to hit and run, covering distance hastily weakening her on the way and initiating ganks.
Silken Bola will cause her attacks to miss and get her swarmed in no time.
Mana Shield fully while Broodmother can fit a 
Diffusal Blade to burn away all of Medusa's mana.
Spin Web will allow Broodmother to pick her own fights and sometimes slip away to ambush Medusa.
* Even though Medusa can hunt down Spiderlings easily when given enough range,
* Medusa usually does not build a Black King Bar to benefit from
Additional:
*
* Though Medusa's Split Shot and Mystic Snake can help Medusa deal with Broodmother's spiderlings, Broodmother will create too much of them for her to handle, allowing her to outnumber Medusa's targets from Split Shot and shield her team in process.
Monkey King
* Heroes with blind of some sort can be a bad choice for Monkey King to go on:
Broodmother, 
Riki, 
Keeper of the Light.