Statesman/other versions - Bruce Willis.
Manticore/Chimera - Nicholas Cage.
Back Alley Brawler/Marauder - Terry Crews.
Infernal/Infernal - Keith David.
Valkyrie/Battle Maiden - Uma Therman.
Citadel/Luminary/Seige/Nightstar - Stephen Hawking.
Synapse/Nueron - Ryan Reynolds.
Faathim the Kind - Leonard Nemoy.
Lord Recluse - Patrick Bateman.
Kalinda - Terri Brosius.
Arbiter Sands - Keanu Reeves.
Capn' Mako - Hugo Weaving.
Black Scorpion - Jack Black.
Wretch - Vin Deisel.
Ghost Widow - Rebecca Romijn-Stamos.
Agent Indigo - Milla Jevovich.
Agent Crimson - Sam Jackson.
Silver Mantis - Lucy Lui.
Snaptooth - Dane Cook (for reasons.)
Dr. Vazhilok - Ralph Fiennes.
Lilitu - Barbara Goodson.
Countess Crey - Michelle Pfieffer.
Rularuu the Ravager - Chuck Norris.
Romulus - Gerard Butler.
Malaise - Johnny Depp.
Lord Nemesis - Sir Patrick Stewart.
Lanaru the Mad - Sean Bean.
Mother Mayhem - Lynda Carter.
Mr. Yin - Jackie Chan.
Penelope Yin - Lucy Lui.
Flambeaux - Megan Fox.
Johnny Sonota - Richard Cheese.
It's all I have written down from the extensive help chat.