Legion

Now the thing everyone is afraid of, David takes a cult and a time traveller and tries to go back far enough to have been someone else.

The final season gives him a way out: Switch, a mutant who can walk backwards through time, and a plan to rewrite his own past before any of it happened. Division 3 and his former friends are trying to stop him, and the Time Eaters are trying to stop everybody.

It is eight episodes and it ends the series on the only question that was ever really being asked, which is whether a person who has done harm can be given a version of themselves who did not.