Zelgadis Greywords (ゼルガディス・グレイワーズ, Zerugadisu Gureiwāzu?) is a fictional character from the manga, light novels and anime Slayers. He is voiced by Hikaru Midorikawa in the original version. In the dub, he was originally voiced by Daniel Cronin. However, after finishing episode 10, the production came to a halt, and was resumed only a year later, while the staff has lost contact with Cronin during that time. They hired Crispin Freeman as a replacement who gave the character a darker voice and he continued to voice Zelgadis for the remainder of the series.

Source: Wikipedia