
Quick answer — Takuma Takewaka voices Amon in Witch Hunter ROBIN, Kaoru Morita in Honey and Clover, Anton Claude in Phantom: Requiem for the Phantom and 3 more characters.
Takuma Takewaka voices Amon (Witch Hunter ROBIN), Kaoru Morita (Honey and Clover), Anton Claude (Phantom: Requiem for the Phantom), Uroyuki Shinoda (The Sky Crawlers), Raina Cromwell (Dragonaut -THE RESONANCE-), Hibiki Saku (IDOLM@STER: XENOGLOSSIA).
Amon is voiced in Japanese by Takuma Takewaka.