oh shoot
I'm sorry
I forgot about the scene between him and Maehdros
yeah, bad example
its been a while since I've read it
okay, to spare you the search of looking it up, Morgoth comes back and is defeated by Tulkas, Earendil, and Turin, who avenges his family
the more important part is that Yavanna remakes the trees and Feanor surrenders the Silmarils willingly to do so
so yeah, he does get a positive ending to his arc