
Quick answer — Ken Yamaguchi voices Ein in Fist of the North Star 2, Nigel Kirkland in Bubblegum Crisis TOKYO 2040, Decoe in Sonic X and 2 more characters.
Ken Yamaguchi voices Ein (Fist of the North Star 2), Nigel Kirkland (Bubblegum Crisis TOKYO 2040), Decoe (Sonic X), Nelson Thorndyke (Sonic X), Ebifurya (Dragon Ball Z: The World's Strongest).
Ein is voiced in Japanese by Ken Yamaguchi.