Eh, probably Jean at this point, because she can more than likely beat him to the punch, but that might change again once Legion S3 drops later this year.
I want to see how the mechanics of that self-warning system they've hinted at in the trailers works. Because it could potentially be one of the most broken abilities ever, depending on the mechanics of it and what the requirements are. It's basically precog, but not quite, because you are not actually seeing visions from the future. Your future self is actually telling you what happened, which is the present/past from their POV.