
Quick answer — Mayu Minami voices Kai in The Eminence in Shadow Season 2, Fuki in In the Heart of Kunoichi Tsubaki, Rushd in Fate/Grand Order Divine Realm of the Round Table: Camelot - Wandering; Agateram and 1 more characters.
Mayu Minami voices Kai (The Eminence in Shadow Season 2), Fuki (In the Heart of Kunoichi Tsubaki), Rushd (Fate/Grand Order Divine Realm of the Round Table: Camelot - Wandering; Agateram), Vanity (Kizuna no Allele).
Kai is voiced in Japanese by Mayu Minami.