Loki stands as one of the most popular characters in the Marvel Cinematic Universe, and he will almost certainly have a part to play come Infinity War. One of the best theories surrounding Loki's role in the two-parter, then, has him making the final transition from all-out villain to anti-hero and finally hero, as he sacrifices himself to save Thor when Thanos threatens to kill the latter, realising that Thor is essential to the saving of the universe. It would be a bold move to take Loki down this path, of course. Some versions of this theory even peg Loki as having played something of a long con the entire time he's been on our screens - that, really, he's the hero of the MCU and that he assumed power over Asgard at the end of Thor: The Dark World for some higher purpose that has yet to be revealed. His real plan, all along? To stop Thanos... at all costs. Marvel have been nudging Loki towards the lighter side of things ever since The Dark World, so it stands to reason that - ultimately - he could go out in a blaze of glory. Fans would probably prefer that than for him to remain villainous until the very end, right?