The Welsh actor stars as Bruce Wayne and his crusading alter-ego in the final instalment of Christopher Nolan's trilogy 'The Dark Knight Rises', and although Batman is a force for good in Gotham City, Christian believes he could also be a baddie because he is so filled with rage.
He told the Daily Mirror newspaper: ''He's almost a villain and takes it to The Edge where he can do great wrong but he has this altruism holding him back from doing that.
''He dresses in the Batman suit because he feels monstrous and creates a monster to represent that rage and keep it away from his own personal life.
''There are so many stories that can be written in that vein.
''We could continue endlessly with this but Chris has written a wonderful final chapter and this is the right time to say goodbye.''
Christian also revealed viewers can expect to see a very different Bruce Wayne/Batman in the latest movie as he is still grieving for his murdered love Rachel Dawes (Maggie Gyllenhaal).
He said: ''He's filled with remorse, he's become a recluse, he's given up and completely quit. He's in very poor health physically and mentally.''