First Appearance: Chapter 9
Osuki is a Rumelian warrior with a hot temper and a strong desire to protect his people by any means necessary, including force. Having watched the Rumelians persecuted and exiled by the Deskunte, he is deeply resistant to the idea of coexistence and pushes aggressively for the Simurians to take what they need from Earth. His willingness to force confrontation — particularly his unauthorized entry into Tokyo and interference with the Great Purification Ritual, which he believed was killing Kalyans — is directly responsible for escalating the human-Simurian crisis. He is later casually knocked out with a single Black Flash from Yuji Itadori when he attempts to attack him. Osuki's arc does not end in defeat so much as irrelevance: a man whose worst fears drove him to create the very catastrophe he feared, and who is ultimately just outclassed by a world that has moved past the binary he could not escape.
Osuki's specific technique has not been disclosed. He is noted to be skilled enough that surviving Yuji's opening attack — which incapacitated every other sorcerer in the area — is itself treated as a mark of his competence, even if he then loses immediately upon engaging Yuji directly.
