One of my leads is a trickster god who was long ago bound in a mortal host. While they can't age and he would always heal/revive his vessel, he can't leave either, and, limited by having an actual body, he can no longer reach the realm of the other gods. (They bound him because they received a prophecy that one day he'd destroy them, so, being genre blind morons, they went "let's make him powerless even though he never hurt us, there is no way this might piss him off".) After 4000 years of roaming the Earth and becoming almost one with his elven host, he suddenly gets most of his powers back after a cataclysmic event. Still not at full power, but now he can finally try to get back at the bastards. He's trying to find a weapon that can actually kill gods, but he also struggles with his changed nature. He had grown very fond of his "prison" and since they can never be separated, wants him happy. Meanwhile, the elf had lived far beyond even what's normal for his species. So he's kind of a dual character - the two halves are not completely merged. I'm a bit wondering what his goals would be beyond revenge, because he definitely doesn't want to destroy the world or anything - he had come to like it more than his old home, and he cares about people a lot. He might even fall in love, although it will almost certainly end badly.