Loki

Granted, he is one of the best villains (if not the best) presented by the MCU. But still "“ didn't it seem to you too that his character became a bit tiresome during Thor: The Dark World? So maybe Thor: Ragnarok will be the best time for him to say his goodbyes. Sure enough, some fans might be angered, but if this is the final installment in the Thor franchise, why shouldn't it end with a bang?

Loki might as well die seeing the errors of his way and opposing a threat that he knows he cannot stop, just to buy Thor some time. Sounds good, doesn't it?