Stheno (Greek for "Forceful") is a character from Fate/hollow ataraxia, and can be summoned as an Assassin-class Servant in Fate/Grand Order. Her Noble Phantasm is "Smile of the Stheno", a powerful debuff and charm against a male opponent.
Has a younger twin sister, Euryale, and a younger sister, Medusa. Depicted as a purple haired girl with purple eyes, twintails, a headdress and white dress. The difference between her sister is the black rose ornament, the slit, and arm decoration is on her left side.