First of all Master Chief has to take off his helmet. You have to the main characters face.

Master Chief - Matt Damon
Cortana - Charlize Theron
Sergeant Johnson - Denzel Washington
Miranda Keyes - Michelle Monaghan
Jacob Keyes - Ed Harris
Lord Hood - Anthony Hopkins
The Arbiter - Keith David

Other Choices:
Master Chief - Christian Bale
Cortana - Keira Knightley
Sergeant Johnson - Samuel L Jackson, Will Smith

Miranda Keyes - Evangeline Lilly, Natalie Portman
Jacob Keyes - Harrison Ford, David Morse
Lord Hood - Clint Eastwood, Sam Shepard

Please tell me your thoughts on my cast, and if you want please put the full cast you would want.