From Dota 2 Wiki
- Anti-Mage's 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.
- Unlike other illusion heroes, Tempest Double won't be destroyed by Stone Gaze since it is considered as clone but not illusion.
- He can cancel spellblock from Linken's Sphere with his Flux and other Flux can slow her, making Phase Boots useless. Especially with Spark Wraith.
- Arc Warden has advantage as farming with twice Midas, and bullying Medusa with his double item using.
- EMP 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.
- Heroes who don't build escape or spell immune items, such as Medusa, will be caught by Earthbind easily.
- Meepo has enough time to Poof away to his clone if Medusa trying to Stone Gazing him. In the other way, Medusa can counter Meepo's initiating with Stone Gaze also.
- Level 4 Mana Burn burns 38,5% of Medusa's mana every 4 seconds if Medusa only increases her mana pool with intelligence. Additionally, 60% of the Mana Burn damage gets mitigated by Mana Shield, burning even more mana.
- Mystic Snake and Split Shot is uncontrollable damage, possibly proccing Spiked Carapace. However, they do not target an invisible Nyx.
- Medusa lacks single target damage, making Nyx with Aghanim's Scepter extremely hard to deal with if Medusa is your main damage.
- Arcane Orb and Sanity's Eclipse reduces Medusa's mana.
- Astral Imprisonment will not interrupt Stone Gaze and will petrify you if you're facing towards Medusa's ( usually Outworld Devourer himself while trying to cast it and after ) direction before she was banished, but it will stop her from getting a good position
- 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 your team in the process.
- Medusa is especially vulnerable to Essence Shift, as both Strength and Intelligence contribute to her effective HP.
- Dark Pact when timed right can be used to dispel Stone Gaze right after it petrifies you, allowing you to keep attacking her throughout the duration.
- Sniper can outrange both Medusa's arrows and Stone gaze, allowing him to lock her down during a teamfight.
- Heroes with mana burning abilities will make Medusa much less tanky: Lion, Bane, Keeper of the Light.
- Heroes that build Diffusal Blade will also make Medusa much less tanky: Riki, Naga Siren, Terrorblade, Juggernaut, Spectre.
- Diffusal Blade burns away the mana Medusa needs for Mana Shield.
- Necronomicon provides mana burning summons, and Medusa is especially vulnerable to getting hit with Last Will.
- Heaven's Halberd disarms Medusa for a long 5 seconds.
Good against...Chaos Knight
- Medusa is the hard counter to Chaos Knight because of Stone Gaze kills (not even petrifies) his illusions and Mystic Snake (when upgraded by Aghanim's Scepter) kills them instantly. And Chaos Knight is not a good Diffusal Blade carrier in general.
- Enchantress often has a small army of neutral creeps, allowing Medusa to hit her with a later bounce of her Mystic Snake.
- Enchantress passive Untouchable is easily avoided by Medusa. Simply target another enemy hero or creep, and let split shot hit her.
- Lifestealer is very immobile hero making him hard to catch Medusa.
- Stone Gaze pierces Rage making him unable to stay and fight her and wasting cooldown.
- Completely negates the burst damage from the shotgun build as mana shield blocks all damage before reductions
- Mana shield effectively counters Reaper's Scythe, as it can tank 60% of the damage. With sufficient mana, Medusa can survive the Scythe at 15%/17%/19% health (before reductions).
- Heartstopper Aura does not chip away at Medusa's mana.
- Necrophos has a movement speed equal to Medusa, and is easy to chase down with a slowing item in Medusa's inventory.
- Medusa is one of Sven's primal counter since he relies on man-fighting which is prevented and kited with stone gaze
- Also has a small mana pool and mystic snake does pure damage while a unit is petrified, a minor buff that is useful in case he used warcry
- A farmed Medusa will be a very hard kill for Sven forcing him to go on others while she chips away at him, usually building Eye of Skadi will leave Sven very slow and soon dead
- Medusa's Split shot allows her to focus on killing the tombstone while still dealing damage to the enemy heroes, or simply ignore the tombstone and allow her split shot to prevent the zombies from building up.
- Another example, mana shield negates all damage before reductions meaning that Corrosive Haze won't do much unless Medusa is completely out of mana
- Mana shield can safe medusa from enigma black hole.
- Medusa split shot can kill Demonic Conversion creep.
- When medusa aready cast he ultimate stone Gaze and enigma ulti him in front his face, medusa has a chance to stun enigma.
- Medusa Mystic Snake can be usefull to kite axe cause axe has small mana pool,especially when in lane.
- Mana shield can make medusa tank againts Berserker's Call and Counter Helix.
- Heroes that rely on illusions to deal damage will find their illusions destroyed by Stone Gaze and Split Shot: Chaos Knight, Naga Siren
- Heroes that rely on summons. A few summons, such Lycan wolves allow Medusa to bounce her Mystic Snake between them to hit the hero for additional damage. Many weak summons, such as Broodmother force the group to tank Medusa's split shot.
- Heroes that rely on Black King Bar to survive teamfights.
- In theory Medusa counters all Melee heroes, even though that is not the case with Mana-burning heroes and heroes with escapes, Medusa can outfight even Anti-Mage if he gets petrified.
Works well with...Earthshaker
- Deals area damage with ultimate and can stun/disable to cast Stone Gaze and make it easier to freeze enemy heroes.
- In late game when is Void's Chronosphere can kill enemies easily.
- Berserker's Call can force enemies to face Medusa during her Stone Gaze.
- Precision Aura amplifies Medusa's Split Shot.
- Drow Ranger's midgame strength allows Medusa to farm safely, then take the lead once Drow Ranger's relative strength drops in the late game.
- During teamfights, casting Disruption upon Medusa creates a pair of illusions with Split Shot and 80% of her base damage.
- Shadow Demon can stack 2-3 jungle camps at the same time, speeding up Medusa's farming phase.
- Stoned enemies are immune to magical damage, but Shadow Poison can still build stacks during the Stoned phase.
- Witch Doctor's ultimate deals physical damage, so if Medusa managed to petrify a bunch of enemies with the given physical damage bonus, Death Ward can shred through enemies especially with Aghanim's Scepter
- Heroes that deal pure damage like Tinker's Aghanim Laser upgrade can give him enough time to cast it a couple of times or Outworld Devourer can deal the full damage of his Arcane Orb and stack a lot of intelligence for those 3 seconds of Stone Gaze
- Everyone with good physical damage and lock down for a good Stone Gaze
- Abilities that grant sustain or heroes with sustain to keep the enemy kited and distracted while Medusa slowly destroys them
- Guardian Greaves restores both health and mana to Medusa, doubly effective as a sustain item since she can tank with Mana Shield.