Sam Liu Director CCH Pounder Amanda Waller Voice Allison Mack Power Girl Voice Clancy Brown Lex Luthor Voice John C. McGinley Metallo Voice Tim Daly Superman Voice Kevin Conroy Batman , Bruce Wayne Voice Xander Berkeley Captain Atom Voice Corey Burton Captain Marvel , Solomon Grundy Voice Stan Berkowitz Screenwriter Alan Burnett Producer Michael Goguen Producer Bobbie Page Producer Benjamin Melniker Executive Producer Sam Register Executive Producer Bruce Timm Executive Producer Michael E. Uslan Executive Producer Christopher Drake Original Music Margaret Hou Film Editing Andrea Romano Casting