Kirei Kotomine, summoned as Grigori Rasputin, is a Catholic priest and a servant. A natural born psychopath, he once struggled with his dark desires while doing his best to remain as normal as possible on the outside. As a servant, he's more open about his twisted interests, free from his mortal coil. Unlike when he was alive, he understands the idea of pleasure a bit more than he used to. Aided by Grigori Rasputin's salacious reputation, Kotomine has no issue with idea of pleasing his master in any way they may see fit.