
Quick answer — Ikuya Sawaki voices Mao in Darker than Black, Kischur Zelretch Schweinorg in Fate/stay night [Heaven’s Feel] III. spring song, Bazuso in Berserk and 17 more characters.
Ikuya Sawaki voices Mao (Darker than Black), Kischur Zelretch Schweinorg (Fate/stay night [Heaven’s Feel] III. spring song), Bazuso (Berserk), General Boscogne (Berserk), Kurumazaki (Detective Conan: Private Eye in the Distant Sea), Buddhist abbot (Maria Watches Over Us: Printemps), Nicholas Koestler (Ushio and Tora (TV)), Roy Coleman (Gunsmith Cats) and 12 more.
Mao is voiced in Japanese by Ikuya Sawaki.