Have you ever heard the tale of the Four Heroes?
Everyone thinks they know the ending. Mario, Peach, and Bowser destroyed the Chaos Heart, and defeated the menace Dimentio.
But was that really the end? Of course not. We wouldn't have much of a story, otherwise.
(The Human tag was put there because Dimentio is kind of human. Maybe.)
(Dimentio is from the game Super Paper Mario. Spoilers for the ending of that game.)