TMNT (2007) ending / spoiler
Max Winters, wants to break the millenial curse over him and his kin. His siblings twig that...no more curse...no more eternal life, so try to stop him from undoing their hex by substituting Leo for the thirteenth monster (used to undo the doomed immortality). Our heros rescues him and join forces with the footclan to foil them and send the true thirteenth monster along with the other twelve back into their own reality along with Winter's brothers and sister. On doing this Winters crumbles to dust.