Yakiri is the son of Nyx Tiamat Xyz (non-human from the Dimensional Corridor born in 1867) and Oblivion Flame O'Neill (b. 1872 d. 1971 (!!!) ). Oblivion is the son of Aino Schelaine Shimakaze (b. 1845 d. 1975), who was a princess, and Syne Sóirum Sword Schism O'Neill (b. 1848 d. 1920), a total BADASS (moreso than fiction's current most badass character IRL).