Medomai

Rider is a Servant.

She is the Servant of Shinji, first seen scouting around Homurabara Gakuen. Rider is silent, sultry, and vigilant, never hesitating to shield her Master from harm. With Shinji incapable of lending any Prana to her, she is forced to seek alternative means to augment her abilities. To compensate for this weakened state, Rider employs covert battle tactics and takes full advantage of any territory around her. Her weapon of choice is a pair of long iron nails fastened to opposite ends a single chain, which she effectively thrusts from distances.
Her real name is Medusa, the Gorgon from Greek mythology. Medusa, along with her sisters, Stheno and Euryale, were born from the wishes of mankind for ideal goddesses, contrasting the flawed gods of Olympus. All three Gorgons were blessed with beauty, but unlike her sisters, Medusa was mortal, and fated to grow older and taller over time. Medusa was also cursed with Mystic Eyes, which transmute all living flesh under her gaze into stone, requiring her to wear a blindfold. Because of these differences, she was bullied by her older sisters. At one point, Medusa was given Pegasus as a gift from Poseidon.