The Over a Hundred Teenage Mutant

Finny's experiments give him immortality of some sort, keeping him the same age forever. In the modern world, he's found by the School and recaptured. There he meets not only Ari and Jeb, but Angel, waiting for Max and the gang to save her. Undergoing painful experiments, by the time they arrive, Finny has a new set of wings and a power he can't control. He has a new family though.