Omaha, Nebraska power metal act Cellador was initially forged under the title Apostate in late 2002 by founding guitarist Chris Petersen and vocalist / bassist Josh Krohn. The group underwent various line-up changes, including tenures for singer Michael Gremio, singer Warren Curry, and drummers Albert Kurniawan and and bassist Valentin Rakhmanov. Guitarist Sam Chatham was enrolled in May of 2004 with drummer Dave Dahir being inducted in June. Singer Warren Curry was replaced by Michael Gremio in December 2005. Mika Horiuchi replaced Rakhmanov as bassist in 2007.