Rider

ライダー

Spoiler

serves as the Rider-class Servant for Aro Isemi in the Second Holy Grail War of Fate/Prototype.
Despite his sociable manners, emotional sensitivity, and gentle nature, he possesses a flaw: once motivated to act, he will not cease until he has exerted every ounce of effort and beyond. In this regard, he is also an anomaly. After deciding to soil his hands with wrongdoing, he became capable of killing innocents while maintaining a gentle demeanor and a smile.