Or as some kind of madness, alternate personality, possession, etc...
[idea]The character is a berserker. During cut scenes, she is never in a rage. During play, she is never not
in a rage. Whenever the player tries to do something the character would not do, ie hurt an innocent, she will actually struggle against the character's control until it become irrelevant. The player is not
the character, they are the berserk rage, a separate entity altogether from the character that controls her body during battle, much as the player does during play.