The Story of Zilean
Zilean has a paradox problem. He is a mage from Icathia — the city that opened the Void rift that eventually destroyed it, that produced the catastrophe that remade the world's relationship with the Void — who found a way to move through time in an attempt to prevent the Icathian catastrophe. He failed to prevent it. He is still moving through time. The failure has not stopped him from trying, but the trying has made his relationship to linear time genuinely non-functional.
He exists in multiple points in time simultaneously, in ways that he can no longer fully separate. He knows things that haven't happened yet. He remembers things from timelines that didn't persist. He is recognizably ancient and recognizably brilliant and recognizably not entirely present in any given moment because some of him is in another moment. The sand in his hourglasses is time itself, which he can accelerate or rewind around him, aged or restoring people at will.
He is still trying to fix Icathia. This is the thing he has never stopped. Every other engagement, every other use of his abilities, is conducted in parallel with the project of untangling the historical knot that destroyed his home. He knows more about the Void's origins than anyone alive, and he is using that knowledge toward a goal that may be impossible, in a manner that has made him impossible to have a normal conversation with. He is kind, in the specific way of someone who has seen many ends. He is also very busy, in many times at once.