Medusa (メドゥーサWP, Medūsa?), Class Name Rider (ライダー, Raidā?), is the Rider-class Servant of Sakura Matou in the Fifth Holy Grail War of Fate/stay night. Due to Sakura's unwillingness to participate as a Master, Shinji Matou is instead given control over Rider. She only truly acts as Sakura's Servant when their connection is revealed in the Heaven's Feel scenario. She is one of the Servants of Ritsuka Fujimaru of the Grand Order conflicts of Fate/Grand Order.