
Quick answer — Ichiro Murakoshi voices Mercy Haku in Lady Oscar: The Rose of Versailles, Staden in Legend of the Galactic Heroes: Overture to a New War.
Ichiro Murakoshi voices Mercy Haku (Lady Oscar: The Rose of Versailles), Staden (Legend of the Galactic Heroes: Overture to a New War).
Mercy Haku is voiced in Japanese by Ichiro Murakoshi.