It's all about Riddick, a badass anti-hero with eyes that see in the dark, kicking alien butt while trying to save the universe from evil forces.
Vin Diesel personally handpicked Judi Dench for the role of Aereon. He was such a fan of her work that he flew to England personally to offer her the role.
The role of Kyra was originally supposed to be played by Jaimie Alexander, but due to scheduling conflicts, the role eventually went to Alexa Davalos.