Invoker
* Broodmother can kill Invoker easily in the early game with her 
Spawn Spiderlings and her spiderlings.
* Broodmother is both an 
Orchid Malevolence and a 
Nullifier carrier. As she can farm it early, she can kill Invoker easily.
Medusa
* Webbed areas can be used to hit and run, covering distance hastily weakening her on the way and initiating ganks.
* Even though Medusa can hunt down Spiderlings easily when given enough range, 
Silken Bola will cause her attacks to miss and get her swarmed in no time.
* Medusa usually does not build a Black King Bar to benefit from 
Mana Shield fully while Broodmother can fit a 
Diffusal Blade to burn away all of Medusa's mana.
Additional:
* 
Spin Web will allow Broodmother to pick her own fights and sometimes slip away to ambush Medusa.
* 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.
Invoker
* Invoker is heavily dependent on his spells, making him useless during 
Global Silence, as well as interrupting Invoker during his combo.
* 
Arcane Curse is particularly deadly, because Invoker will continuously lose health if he keeps invoking and casting new spells.
* 
Last Word will silence Invoker when he casts Invoke, interrupting his combo.
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.
Invoker
* Anti-Mage's mobility and magic resistance make him nearly impossible to kill alone.
* Invoker's spells cost a lot of mana, and Invoker himself has a lot of mana. This means Invoker and his team are vulnerable to 
Mana Void's heavy damage.
* 
Blink allows Anti-Mage to escape from Invoker's combo if he doesn't have disables.
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.
Invoker
* 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.
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.
Invoker
* Heroes with silence: Death Prophet, 
Riki, 
Drow Ranger.
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.
Invoker
* 
Blade Fury, similar to Rage, grants immunity to Invoker's spells and can dispel some debuffs as well.
* 
Omnislash renders Juggernaut invulnerable to Invoker's spells and can easily take Invoker down.
Additional:
* Juggernaut's instant spell immunity from Blade Fury. helps him dodge Invoker's combos. He can dispel the disables from 
Cold Snap and 
Deafening Blast and dodge the damage from 
Chaos Meteor, as well as walk through 
Ice Wall.
* Juggernaut's high DPS allows him to kill split pushing 
Forge Spirit(s) effortlessly, and his high armor prevents them from being a threat to him.
* However, Invoker can hit Juggernaut with 
Sun Strike through Blade Fury, making the 
Tornado and Sun Strike combo a threat if he does not dodge Tornado.
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.
Invoker
* 
Tidebringer pressures Invoker easily in lane due to Invoker's low health and armor in the early game.
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.
Invoker
* 
Crippling Fear is a good way to shut down and gank Invoker in the early game..
* 
Void deals good damage to Invoker and makes escaping harder.
* With 
Hunter in the Night and Void, Invoker can't get away from Night Stalker and won't be able to catch him with Sun Strike during the night.
Invoker
* Queen of Pain usually outlanes Invoker, giving her team a significant early game advantage while Invoker is still farming.
* 
Blink allows Queen of Pain to escape from Invoker's combo if he doesn't have disables.
Invoker
* Quas-Exort Invoker is also a good matchup due to the fact he has no 
Wex to run faster due to the movement impairment on his stealth. The Forge Spirit and Cold Snap combo doesn't harm her as well since you can drain Invoker's HP with Spirit Siphon which forces him to retreat.
* Silence also prevents Invoker from using 
Invoke or casting his main spells temporarily. There is no way Invoker can block it unless he has 
Eul's Scepter of Divinity to cyclone himself or has help from allies.
Invoker
* Time Walk can easily avoid Invoker's combo damage if doesn't have disables.
* Chronosphere will reveal Invoker during 
Ghost Walk.
* All of Invoker's hidden cooldowns are affected by Time Dilation, so Faceless Void can easily slow him down a lot.
Additional:
* 
Time Dilation prevents Invoker from further invoking for the entire duration of the debuff, as well as massively slowing Invoker based on the large amount of spells he has.
* 
Time Walk will completely negate Invoker's combo damage.
* If Invoker is caught in 
Chronosphere, he will most likely be the primary target due to the large teamfight contribution he can provide.
Invoker
* 
Nether Ward on its own can greatly hinder Invoker from casting many of his abilities, at least until he gets a significant amount of HP or is under the protection of spell immunity from Black King Bar
* 
Life Drain provides True sight, revealing Invoker through Ghost Walk, and forcing him or his allies to use an ability or item to interrupt its channeling
* Outside of Nether Ward's range, Invoker shall have the advantage, as Invoker has Tornado to purge Pugna's 
Decrepify when it is used defensively, Tornado or Cold Snap to prevent Pugna from channeling Life Drain
* A poorly used Decrepify on Pugna's allies means Invoker's abilities can be used to deal more damage to them.
Additional:
* Because Invoker relies on casting a large amount of spells to contribute to fights, Nether Ward can force him to not cast anything at all or take a large amount of damage to cast spells.
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.
Invoker
* Earth Spirit is a dangerous foe to encounter for Invoker in the early stages of the game. Since Invoker needs to gain levels as fast as possible and is not very strong in the early game, Earth Spirit can use his incredible early game power to gank Invoker and ruin his game plan.
* Earth Spirit combines stuns and silences with his spells and can apply them from a great distance. This is bad for Invoker as he is dependent on a smart usage of his spells with Invoke and Earth Spirit can disrupt his combos easily.
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.
Invoker
* Templar Assassin can easily counter Invoker's last hitting process in the early game with 
Refraction. Refraction also negates the stun from Cold Snap, since it will need to deal damage in order to apply its stun.
* Additionally, Refraction completely blocks damage from Sun Strike should Invoker try to finish her off, provided she activate Refraction beforehand.
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.
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.
* In addition to easily breaking her commonly bought Linken's Sphere with its low cooldown, 
Mana Drain can quickly drain her Mana Shield, making her far less tanky.
* Mana Drain, along with Hex, destroy illusions instantly, which may be extremely helpfull and efficient against core builders of Manta Style, like Medusa herself.
Invoker
* 
Bounty Hunter and 
Slardar both have ultimates (
Corrosive Haze and 
Track) that reveal Invoker through Ghost Walk.
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.
Invoker
* Heroes with long lockdowns: 
Shadow Shaman, 
Legion Commander.
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.
Invoker
* Bounty Hunter and Slardar both have ultimates (Corrosive Haze and Track) that reveal Invoker through Ghost Walk.
Medusa
* Other heroes who has armor and slow debuffs won't allow Medusa to disengage from combat: Tidehunter, Bristleback, Slardar.
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.
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.
Invoker
* Heroes with silence: Death Prophet, Riki, Drow Ranger.
Medusa
* Other heroes who has armor and slow debuffs won't allow Medusa to disengage from combat: Tidehunter, Bristleback, Slardar.
Invoker
* 
Astral Imprisonment allows Outworld Destroyer to save himself or ally from Invoker's combo, or remove Invoker from a fight temporarily.
* 
Arcane Orb's pure damage will deal a lot of damage against Invoker's mediocre strength gain.
* E.M.P. is useless against Outworld Destroyer by activating 
Equilibrium.
* However, be aware that 
Sanity's Eclipse will most likely not deal any damage at all, due to Invoker's high intelligence gain compared to Outworld Destroyer's.
Invoker
* Any heroes with high intelligence, such as Invoker and 
Pugna.
Invoker
* In the early to mid game, Invoker is defenseless against Storm Spirit's ganking with 
Ball Lightning and Orchid Malevolence.
Invoker
* Heroes with mana burn: 
Nyx Assassin, Invoker, Outworld Destroyer, Pugna, Lion
Invoker
* Ice Wall can slow down 
Charge of Darkness in its tracks at max level, allowing counterplays such as Cold Snap to end the charge, bursting down with Tornado, Meteor, and right clicks, or even teleporting back to spawn to drag Spirit Breaker into the fountain.
* Cold Snap (if timed right) and Invoker's other disables like Tornado can interrupt Charge of Darkness, especially since Charge is telegraphed by the symbol appearing over head.
Additional:
* Cold Snap allows Invoker to interrupt Charge of Darkness and Nether Strike.
* Tornado's long range can be used to cancel Charge of Darkness.
* Deafening Blast prevents Spirit Breaker from right clicking and thus proccing his Greater Bash.
Medusa
* If Medusa activates Stone Gaze before Spirit Breaker reaches her with Charge of Darkness, the charge will inevitably fail.
* Mana Shield and overall tankiness allows Medusa to easily survive Spirit Breaker's initiation.
Invoker
* Tornado allows Invoker to purge Necrophos's 
Ghost Shroud, nullifying any benefits he could get out of it
* E.M.P. allows Invoker to burn Necrophos's mana, preventing him from using his abilities constantly
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.
Invoker
* Heroes who can clear the waves of Enigma's Eidolons: 
Lina, 
Luna, 
Dawnbreaker, 
Jakiro, Shadow Shaman, Death Prophet, 
Keeper of the Light, Invoker, 
Leshrac, Puck.
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.
Invoker
* Heroes with naturally low mana can be easily shut down by E.M.P.: 
Sven, 
Tiny, 
Wraith King, 
Omniknight
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.
Invoker
* Invoker's multiple spells can lock down Undying and disable him from doing much.
Medusa
* Split Shot can destroy Tombstone Zombies and Tombstone itself while still damaging heroes.
Invoker
* 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.
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.
Invoker
* Heroes with long lockdowns: Shadow Shaman, Legion Commander.
Invoker
* Invoker's spells will disable and destroy Legion Commander while she's locked in a 
Duel.
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.
Invoker
* 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.
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.
Invoker
* Heroes with long animations can be frequently interrupted with Cold Snap: 
Earthshaker, 
Monkey King, Shadow Fiend Lina
Medusa
* Heroes with a lot of burst damage, especially those who rely on casting spells: Lina, Zeus.
Invoker
* Cold Snap can prevent Timbersaw from using both Timber Chain and Chakram due to the frequent stuns interrupting the lengthy cast animations, as well as stopping him mid-chain. This can negate Timbersaw's attempts to escape or dole out extra ability damage.
* Later in the game, Invoker's heavy magical and pure damage can be difficult to avoid, meaning Timbersaw's armor is less useful.
Medusa
* Enchantress often has a small army of neutral creeps, allowing Medusa to hit her with a later bounce of her Mystic Snake.
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, 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.
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.
Invoker
* Cold Embrace is the perfect setup for all his nukes - Chaos Meteor, 
E.M.P. and especially global Sun Strike.
Invoker
* 
Quas-
Exort Invoker can win the mid lane easily against Alchemist because Quas regeneration will nullify Acid Spray's damage over time and Exort damage bonus will allow Invoker to out last hit Alchemist.
Medusa
* Mana Shield makes it very difficult for Bloodseeker to gain his Thirst bonuses.
* Rupture rarely kills Medusa through Mana Shield.
Invoker
* E.M.P. allows Invoker to burn Wraith King's mana to prevent 
Reincarnation from triggering (only until Wraith King gets his Aghanim's Shard).
* Ice Wall and Cold Snap are particularly crippling for Wraith King as they allow to kite him very effectively, preventing him from dealing melee attack damage.
Additional:
* Invoker can drain Wraith King's mana with E.M.P., preventing him from reincarnating unless Wraith King has his Aghanim's Shard.
* Even if Wraith King survives and reincarnates, Invoker still has an arsenal of spells to lockdown Wraith King, including an easily setup Ice Wall.
* Tornado applies an area dispel to clear skeletons.
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
* Visage's familiars are easy targets to Split Shot.
* Mana Shield will resist Soul Assumption instances without effort.
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.
Invoker
* Heroes with naturally low mana can be easily shut down by E.M.P.: Sven, Tiny, Wraith King, Omniknight
Invoker
* Heroes with long animations can be frequently interrupted with Cold Snap: Earthshaker, Monkey King, Shadow Fiend Lina
Medusa
* Heroes with Linken's Sphere as core item: 
Weaver, 
Morphling, Medusa.
Invoker
* Heroes with long animations can be frequently interrupted with Cold Snap: Earthshaker, Monkey King, Shadow Fiend Lina
Invoker
* Some heroes with extreme range, like Zeus, Invoker or 
Clockwerk, can snipe your allies from anywhere after your Grave has expired.
Invoker
* Heroes that can keep Marci for a long time in one place so she can't pursue her targets, like 
Bane, Lion, Shadow Shaman, Invoker, Disruptor and Kunkka.
Invoker
* Heroes with silence and mana drain abilites, as Ancient Apparition relies entirely on his abilities: Invoker, 
Silencer, Nyx Assassin, 
Skywrath Mage, Shadow Shaman, Lion and etc.
Invoker
* Invoker's E.M.P. is extremely effective against Earthshaker due to his low natural mana.
Invoker
* Heroes with naturally low mana can be easily shut down by E.M.P.: Sven, Tiny, Wraith King, Omniknight
Additional:
* Tornado dispels Heavenly Grace and Guardian Angel from multiple targets.
* Guardian Angel is generally useless against Invoker as he primarily relies on magical damage.
* E.M.P. depletes Omniknight's already small mana pool.
* Invoker's many disables keep Omniknight's team occupied until Guardian Angel times out.
Invoker
* Heroes whose abilities can affect multiple enemies at once: Dawnbreaker, 
Ember Spirit, Lina, Luna, Jakiro, Leshrac, Invoker.
Medusa
* Heroes with disables that ignore spell immunity will render Phantom Assassin quite useless in teamfights throughout the game: 
Axe, Enigma, 
Vengeful Spirit, 
Doom, Bane, 
Beastmaster, 
Pudge, Medusa, 
Warlock.
Medusa
* Heroes with a lot of burst damage, especially those who rely on casting spells: Lina, Zeus.
Invoker
* Heroes with abilities which have a built-in spell immunity: 
Lifestealer, Juggernaut, 
Pangolier.
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.
Medusa
* Hard carries who just want to farm and be left alone will not appreciate Primal Beast, heroes such as Medusa, Drow Ranger...
Invoker
* Invoker's numerous area-of-effect abilities can interrupt Primal Beast, especially while he is in the middle of a team fight, where Primal Beast thrives. (Tornado, Cold Snap, and Ice Wall all help to disable Primal Beast and control him from a distance.
* E.M.P. disintegrates Primal Beast's low mana pool.
* However, Invoker is quite a slow-paced hero and not particularly known for being survivable against a rampaging Primal Beast with Black King Bar.
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.
Invoker
* Any hero with a low HP pool is easy for Tinker to nuke down: 
Crystal Maiden, 
Enchantress, 
Gyrocopter, Lion, Riki, 
Techies, Terrorblade, 
Necrophos, Invoker.
Invoker
* Tinker is relatively helpless against Invoker, as his 
Rearm and 
Boots of Travel can be easily interrupted by Invoker's long range disables, even if he blinks away.
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.
Invoker
* Heroes with high magical or pure damage will bypass Bulwark: 
Timbersaw, 
Dark Willow, Enigma, Invoker, Pugna, Skywrath Mage, 
Tinker, Zeus, Oracle.
Medusa
* Medusa's Stone Gaze forces Mars to choose between getting petrified, or turning his vulnerable back on Medusa.
Invoker
* 
Doom completely takes Invoker out of a team fight, a hero who relies heavily on using abilities and items to contribute in team fights.
Additional:
* Doom is a good way to shut down Invoker, preventing from casting spells and using items for a lengthy time, thus forcing him to invest on Linken's Sphere.
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
* 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.
Invoker
* Heroes who can summon illusions and summons because Terrorblade has no abilities to deal with multiple enemies at once outside Reflection: Shadow Shaman, Naga Siren, 
Broodmother, 
Lycan, Enigma, 
Chaos Knight, 
Phantom Lancer, 
Shadow Demon, 
Dark Seer, 
Nature's Prophet, Invoker, Morphling, 
Visage, 
Grimstroke with Aghanim's Scepter.
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.
Invoker
* Invoker's arsenal of magical spells are troublesome for Sniper who has low HP and high armor, which does not benefit him much against Invoker.
* Besides magical damage, he can be disarmed and repeatedly mini-stunned with Cold Snap, preventing him from reacting.
* Leveling Quas can allow Invoker to lane effectively against Sniper despite right-click harassment.
Invoker
* 
Rage grants immunity from Invoker's spells and can dispel most of the disables such as the armor loss from Forge Spirit and the constant stuns of Cold Snap.
Additional:
* Rage protects Lifestealer from all of Invoker's spells (except for Sun Strike).
Medusa
* Lifestealer's low mobility makes him easy to kite.
* Stone Gaze pierces Rage, wasting its cooldown and making Lifestealer unable to fight.
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.
Medusa
* Mana Shield reduces the effectiveness of Counter Helix.
* Stone Gaze makes it very difficult for Axe to initiate on Medusa and her allies.
Invoker
* 
Corrosive Skin makes Viper receive less damage from Invoker's spells
* Viper can harass Invoker with his 
Poison Attack in the early game.
* 
Viper Strike and Poison Attack can kill Invoker easily if Ghost Walk is on cooldown.
Invoker
* Ice Wall and Ghost Walk can be used to kite and escape from Viper.
* Chaos Meteor and Sun Strike deal heavy damage and can quickly bring Viper down.
* Cold Snap, Tornado, and Deafening Blast are powerful disables that reduce Viper's effectiveness.
* E.M.P. burns Viper's limited mana pool, reducing his potential poison damage.
* Forge Spirits can melt Viper's armor and reduce his durability.
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.
Invoker
* Quas Exort Invoker has high physical damage in the form of Cold Snap and Forged Spirits that allows him to trade hits with Huskar.
* Although Huskar can dispel Cold Snap with Life Break.
* Sun Strike deals pure damage and pierces spell immunity, and Huskar tends to drain his HP, making him a susceptible target.
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.
Invoker
* Invoker's Forge Spirit can negate Flux.
* Provided he does a right combo with Chaos Meteor, Invoker can easily burst down Arc Warden (plus his clone if he spawns it.)
* An early Orchid Malevolence can shut down Arc Warden pretty hard, especially when Invoker has a good lane against him if he kills him early on.
* Deafening Blast and Ice Wall limit's Arc Wardens mobility and damage, crippling him greatly.
Invoker
* Nyx Assassin can simply activate
Spiked Carapace while under many Invoker's abilities to stun him.
Mind Flare, as the spell does more damage based on the target's intelligence.
Vendetta burns a large amount of Invoker's essential mana pool.
* Nyx Assassin takes advantage of Invoker's massive intelligence gain to do tons of damage using
*
Medusa
*
Vendetta burns a significant amount of mana on hit, and the damage from the ability drains Medusa's mana pool even further.
Spiked Carapace if he's within range of Medusa's abilities and isn't invisible.
Aghanim's Scepter extremely hard to deal with if Medusa is the team's main damage source.
Split Shot, Medusa can be easily interrupted by Spiked Carapace during combat, especially during her precious 
Stone Gaze.
Mana Shield, especially if Medusa only increases her mana pool by bolstering intelligence (which has the added bonus of increasing Mana Burn's damage).
Mystic Snake and 
Split Shot can trigger Spiked Carapace.
Medusa lacks single target damage, making a Burrowed Nyx Assassin hard to kill.
* Due to the passive nature of Mystic Snake and Split Shot, it can possibly proc Nyx's
* Medusa lacks single target damage, making Nyx with
Additional:
* With her passive
* Mana Burn quickly destroys
* Uncontrollable damage from
*