Kirei Kotomine is the Master of Assassin in the Fourth Fuyuki Holy Grail War of Fate/Zero. He later forms a contract with Archer after Assassin's defeat. This contract persists into the Fifth Fuyuki Holy Grail War of Fate/stay night, where he is also appointed overseer of the Holy Grail War and forcibly takes the contract of Lancer after dealing a fatal wound his Master, Bazett Fraga McRemitz. While he is supposed to be an impartial mediator, he works in the background of the Holy Grail War to meet his own goals. He is a main character of Fate/Zero and a major antagonist of Fate/stay night. Kirei wears simple vestments and a golden cross around his neck during the Fourth Holy Grail War, and he wears a cassock as of the Fifth Holy Grail War. Participating in the 4th Holy Grail War at the age of 28. He is noted to be rather tall, standing at 185 cm in his mid twenties, and experiencing an unnatural eight centimeter growth spurt to 193 cm after the Fourth Holy Grail War for an unknown reason. Unknown to all those around him, Kirei was born defective, possessing a warped mind since birth. He is an evil person, but not a villain. He is deviant, but not inhuman. Despite his personal accomplishments, he never felt satisfaction. Despite his best efforts he could not enjoy what other people found happiness in, and instead found himself drawn to negative emotions like the pain of others. He is able to act like a normal person, even bringing pride to his father, but he intrinsically does not feel the same happiness others do. He is very similar to Shirou in that he is a void human being without a clear sense of self, and can be called the opposite extreme of Shirou. If Archer is a light embossing of Shirou's defects, then Kotomine could be said to be the wall exposing those defects by darkness. He also pursued Kiritsugu fervently, mistakenly believing that Kiritsugu possessed the same hollowness.