Digest to ‘The Tale of the Titaness Gorgon Medusa'
Children of Gaia (Earth) and Uranus (Sky) — the Titans Phorcys and Ceto — had six daughters (The Phorcydes). Three of them — Pemphredo, Enyo, and Dino — were called the Graeae and were known for their silver hair and beauty. The other three — Stheno, Euryale, and Medusa — were the beautiful Gorgons with golden wings.
( Undoubtedly, the names "Graeae"-"Old Women" and "Gorgon"-"Terrifying" were given to the Phorcydes by the Olympian gods following the Phorcydes defeat. This was done to erase any memory of their once-beautiful nature.)
After the fall of the Titans and the rise of the Olympian gods, the Phorcydes refused to bow to the new rulers. Athena-Pallas, daughter of Zeus and the Titan Metis, envied Medusa's beauty and strength, especially her hair. Poseidon, urged on by Athena, chased Medusa and eventually raped her in a temple where she was hiding. Not satisfied with this, Athena, in her anger, transformed Medusa from a beautiful girl into a monstrous figure with snake hair and a gaze that turned everything to stone.
(By the way, the story of Athena's nickname, Pallas, perfectly illustrates her wild sadistic nature. After she defeated the Giant Pallas, Athena skinned him alive to make her breastplate. She also added the Giant's name to her own as a trophy, which is why she's often referred to as “Pallas” or “Pallas Athena.” She later affixed the head of the Gorgon Medusa to it. The other version is that the breastplate was made from the hide of her "milk grandmother", the goat Amalthea, who nursed her father Zeus as an infant. It's up to you to decide which version sounds less shocking.)
Medusa became an outcast and had to hide with her sisters at the edge of the world, guarded by the Graeae. Once a year, the Gorgons would fly out into the world, and during that time Medusa realized her gaze could turn anything to stone.
Athena inspired Perseus, the son of Danaë and Zeus, to want to cut off Medusa's head, and Hermes helped him find the way. Perseus got magical items from the nymphs: a bag, an adamantine sickle, and Hades' cap of invisibility. Athena also gave Perseus a mirror-like shield so he could see Medusa without looking directly at her.
Using trickery, Perseus forced the Graeae to show him the way to the Gorgons. When he arrived, he cut off Medusa's head. From Medusa's body came the winged horse Pegasus and the titan Chrysaor. Medusa's sisters woke up and tried to chase Perseus, but they couldn't catch him. By the gods' command, Perseus returned all the magical items, including Medusa's head, which Athena placed on her breastplate.
Athena also collected Medusa's blood, which could either save or kill people, and gave it to the healer Asclepius. Asclepius used it to bring the dead back to life, breaking the law of Ananke, the inevitability of fate. This disruption of the natural order of the cosmos angered Zeus and he struck Asclepius down with a lightning bolt to remind everyone of the inevitability of death.