Medusa

Medusa the Gorgon is a ranged agility Hero. Highly item-dependent, she acts as a carry who can potentially strike down entire teams at once while protected by tank-like survivability. Split Shot allows her attacks to hit multiple targets, greatly increasing the potency of damage-granting items. Mystic Snake grants Medusa some presence in the lane and skirmishes, and its mana stealing refunds part of the cost to boot, making it an excellent farming and harrassing tool. Mana Shield protects her from the opening damage of teamfights, and if supplemented with items makes killing Medusa a fatally time-consuming process. Stone Gaze acts as a fantastic defensive mechanism against ganks and initiations alike, with crippling effects on all who dare face the Gorgon.

Tips

 * Mystic Snake can be maxed first as it is Medusa's only nuke and can be used to push your lane.
 * The damage increases per jump, so it is best cast so that it would hit enemy heroes at last, to make them take the most damage. If used for farming, casting it so that it hits the creeps with more health can prevent overkill damage on lower health creeps, making it more effective and faster to farm.
 * Since Medusa does not have much mana and the ability has a high mana cost, it is important to make sure that it hits at least 2 enemies which have mana (e.g. ranged lane creeps), to get some mana restored back. It does not matter if targets with mana are hit as first or at last, since the mana drain is static and does not increase per jump like the damage.
 * The lane creeps have a mana pool of 300, so Mystic Snake can drain 33/42/51/60 mana from them. So in order to get its full mana cost basically refunded, it has to hit at least 5/4/4/3 ranged lane creeps. This means it is also important to hit enemies with the spell in order to not run out of mana during the laning phase.
 * Split Shot is a highly item-dependent ability. Consider spending pre-level 6 points in Attribute Bonus for a small but more tangible boost in power.
 * By activating Split Shot before you use Manta Style or Illusion rune, the illusions gain the Split Shot ability, which is a very good boost in terms of increasing their DPS.
 * Be wary about leaving Mana Shield active in the early game without a high mana pool or some mana regen items. Heavy damage may leave you unable to cast Stone Gaze, which can turn the tides of a gank or teamfight when used correctly.
 * Mana Shield does however provide an immense amount of damage reduction at all levels. An alternative build is to max this by 7 and take a lot of points in stats.
 * The ideal ratio of mana to health is 0.94/0.79/0.68/0.6 mana per health, meaning every consecutive skill point in Mana Shield becomes less cost efficient, consider grabbing a point in your other skill points over another point in mana shield if you already have the ideal mana/health ratio (any more points basically mean wasted mana; do not forget about Stone Gaze and Mystic Snake costs)
 * When pushing, activate Split Shot when attacking towers to whittle down an incoming creep wave.
 * Items built from Ultimate Orb and Perseverance are good for Medusa, such as Linken's Sphere and Manta Style. The bonus stats and regen make Medusa very tanky with Mana Shield active.
 * Medusa's mana pool needs to equal at least 93.75%/78.95%/68.18%/60% of her current health to maximize the damage reduction of Mana Shield, assuming she does not lose mana in any differnet way than by the absobtion of Mana Shield.
 * You should always have a Town Portal Scroll in order to escape incoming ganks and as well as for defending your base. It is especially useful for countering engagements and tower dives, as Stone Gaze severely punishes teams who commit to a fight.
 * It is possible to farm ancients with Medusa at level 1 by putting a point into Split Shot. However, it requires juking into the jungle, and may need more skill to perform in on the Dire ancients.
 * Remember that Petrified heroes take no damage from magical attacks. This is especially important if you have a nuke heavy team as activating Stone Gaze at the wrong time can cost your team a battle that could have been won otherwise.
 * Proper use of Stone Gaze together with Split Shot makes Medusa a great counter to heroes that either summon illusions, purchase Manta style in their item build or rely heavily on their auto-attacks to do damage. Examples of these heroes would be Phantom Lancer, Chaos Knight and Faceless Void. Remember that a successful Stone Gaze clears all illusions from Medusa's vicinity.
 * However, be very wary with its activation - smart users may attempt to use illusions to bait you either by taking you to poor spots or by forcing your ultimate out, which can leave you very vulnerable, especially to heroes like Phantom Lancer as they almost always build Diffusal Blade (making your mana shield much less effective) and he can easily overwhelm you beyond your capacities even with Split Shot active.
 * Power Treads are a valid option for Medusa as she greatly benefits from the stat toggle and increase of attack speed. Phase Boots are great for more active play, but once you can sit in place and auto-attack, Power Treads are better.
 * Magic Wand gives Medusa cheap restoration and stats that she needs early game.
 * Manta Style is an excellent item to build on Medusa to greatly increase her Area of Effect Damage per Second through a team fight. You can dodge projectiles or dispel certain debuffs on yourself and unleash a barrage of auto attacks on the enemy team.
 * Eye of Skadi provides much needed stats to boost Medusa, while Strength and Agility naturally makes her much harder to bring down, Intelligence increases the amount of damage she can absorb with Mana Shield (Up to 60% of each hit) which makes Skadi the ultimate item to tank Medusa and give her the survivability to stand tall and mow down the enemy team.
 * Mjollnir and Maelstrom can be picked up to increase your farming speed while also boosting your damage passively. Mjollnir's Static Charge buff can be applied to yourself when you get focused to provide even more AoE damage to the enemy team, overall Static Charge is fantastic to pick up on any tank.
 * Mask of Madness is an effective farming item, as Mana Shield will mitigate the additional damage taken and increase your movement speed and attack speed greatly.
 * Always make sure to turn off Split Shot when fighting a single target, or else your damage output will be severely undermined.
 * Manta Style is not recommended early. Medusa has low base damage, which is further reduced by Split Shot, and Ranged Illusions also do little damage without a large investment in Agility items, which you likely won't have early on. In some cases, one might want to just buy a Yasha early for a cost-efficient damage/farming item and possibly leave it at that until later.
 * Black King Bar might not be necessary to build in most games, as your tankiness from Mana Shield can allow you to fight for long periods of time despite being disabled. Along with this, it doesn't give much in terms of stats, so other options like Eye of Skadi or Butterfly may be better for Medusa to tank up with.

Trivia

 * While the lore of Medusa is heavily inspired by its ancient Greek counterpart it should be noted that in the early versions of the myth, Medusa was born hideous to primordial sea deities Phorcys and Ceto who are described as cthonic monsters from an archaic world.
 * The mythology that describes Medusa as having incomprehensible beauty was introduced later by the Roman poet Ovid and in that version Medusa did not exchange her beauty for power. Rather after being attacked by Poseidon in the temple of Athena the enraged goddess twisted Medusa's beautiful visage to the point that merely looking at her would turn the onlookers to stone.
 * Medusa's response upon killing Gyrocopter Medus rival 10.mp3 "Snakes on a plane.", refers to the movie of the same name.