Raiden Skin

The Raiden Skin is a tribute to the Metal Gear Solid series. It can be unlocked in Assassin's Creed: Brotherhood by finishing all the training sessions in the Animus Virtual Training Program with at least a Bronze Medal. While the skin appears to be full-body, Ezio Auditore's hair and face remain unchanged, possibly a move by animators to avoid needing to make an entirely separate set of facial expressions for one skin.

The Raiden skin alters several characteristics:
 * While wearing the skin, no Hidden Blades are visible whatsoever.
 * Since the Raiden skin has no visible sheath for Ezio's weapons, all of his equipment will appear to float in midair at roughly three to four inches from his body. Additionally, just as in Metal Gear Solid 4: Guns of the Patriots, Raiden's SOCOM pistol can be seen in the hip-holster, despite the fact that it cannot be used.
 * While not necessarily a change in style, the Raiden skin appears to have a more fluid movement style while climbing and a much blockier style while running. This is most likely the result of movement-conservation techniques used by animators that carried over between character models, since very little of Ezio's legs are visible with his default outfit.
 * In the loading screen after unequipping the Raiden skin, the character model will flip back a cape that isn't there yet, since the idle animations load faster than the skin itself.