|Voice actor:||Hirose Masahi|
|Talents:||Preaching, Chinese Martial Arts|
|Natural enemy:||Ryuunosuke Uryuu|
|Image Color:||Oxidized silver|
Risei has the same eyebrows and mussed mullet as his son, joked as being the Kotomine clan Sorcery Trait. He gives of the appearance of an old soldier better suited to wearing a samurai costume in the Warring States era than a priest's cassock. Even with his cleft chin that makes him look like a character from Ninja Scroll, he "feels like a genuine Japanese person."
Kirei Kotomine's 80 year old father, Risei is a priest in the Church and the regulator of the third and fourth Holy Grail Wars. A friend of Tokiomi Tohsaka's, Risei actively supports him and conspires to ensure that Tokiomi will obtain the Holy Grail in the war, despite the fact that as a member of the Church, he should be ensuring only someone who is worthy of the a powerful artifact like the Grail should be obtaining it.
While he is proud of his son, who has demonstrated himself to be a perfect heir, Risei fails to understand Kirei in any sense. He believes that his son, who has recently lost his wife of two years, may be able to find some purpose in life again by aiding Tokiomi during the Holy Grail War.
Both Risei and Tokiomi, upon discovering that Kirei's command mantra had appeared three years before the start of the war, both came to believe that Kirei was destined to provide Tokiomi with an additional Servant and associated command spells for the upcoming war. Without informing Kirei as to the true nature of the mark that appeared, they transfer Kirei from the Church to the Mages Association as Tokiomi's pupil. Neither man reveals to Kirei that he can also obtain the Holy Grail, instead telling the young man that he is performing a mission for the Church.
As Risei conspires with Tokiomi, they eventually come to see that Caster and his Master prove to be too erratic and threaten Tokiomi's chances of winning the war. To this end, they arrange for Risei to offer additional command spells to the Master who manages to defeat Caster and his Master.
According to Kotomine Kirei in Fate, his father died trying to protect him. As revealed in Fate/Zero, after Caster's defeat, Kayneth Archibald El-Melloi approached Risei to obtain additional command spells. After Risei reluctantly gives what Lord El-Melloi has come for, the Master shoots Risei and leaves him to die in order to implicate Kiritsugu as the murderer. As he dies, Risei leaves behind a message containing a secret password that will provide his son with all the remaining command spells Risei could give out. Kirei arrives to find his father dead and his father's final parting gift, and comes to the conclusion that Risei died trying to protect him. Though Kirei sheds tears realizing his father cared about him till the end, he finds himself feeling the same feelings he felt when his wife died - the desire to have seen them die.
Risei is a practitioner of bajiquan, but he does not utilize it actively in order to kill targets like his son engaging Dead Apostles. He is not an Executor, so he uses it as a form of self-discipline and meditation. He only trains with the goal of being able to fight rather than with the goal of being able to kill, so Kirei uses it in gruesome battles more often than him. Despite his advanced age, his physique is still very muscular.
He, as the supervisor of the Holy Grail War, has a large number of Command Seals recollected from the previous Holy Grail Wars as the inheritance of the Masters who lost their Servants before the final battle. All Command Seals not used in time are entrusted to him and left to his judgement as the one presiding over the Fourth Holy Grail War.
While their existence can already be called a kind of miracle possessing enormous power, they are still a form of exhaustible physical enchantment. This allows them to be transplanted or transferred through incantations. He is able to reserve Command Seals to anyone based upon his own judgement, allowing Masters renew more control over their Servants. The process only requires him to trace the faded marks of the used Command Seals and transfer his own to replace them. The process doesn't come with any pain like receiving them from the Grail, and it only takes a few minutes to complete.
The Command Spells managed by the supervisor are protected by holy prayers and may only be transferred through his permission, so it not possible to seize them through the use of thaumaturgy. Even after Risei's death, Kayneth Archibald El-Melloi is unable to take them. Only those who know the secret holy words, "God is spirit, and his worshipers must worship in spirit and in truth——" from John 4:24, are able to utilize them. Risei leaves the letters "jn424" transcribed in blood, so that it looks to be a secret message of unknown meaning to those not of the Christian faith. Kirei is able to identify it immediately, and upon speaking it, they are transferred one by one while accompanied by dull pain.
- ↑ Fate/Zero material Pages 76-77
- ↑ "Kotomine Risei practiced Bajiquan as a form of self-discipline and meditation. As someone who was not an "Executor", his goal was to train himself to fight, rather than training himself to kill. As a result, his son Kotomine Kirei engaged things like Dead Apostles in gruesome battles more than he did."