his purple move is the best black feed in the game.
his black move places a high damage attack tile on the board at most times. (as long as you don't match it your enemy will take 400+ damage plus strike tiles a turn extra.)
his green move puts down okay strike tiles if you have no better green move, his green isn't important
Pretty much.
His purple power, being 5 AP, is insanely strong. Not to mention some of the best moves in the games are Black (BP, Luke Cage, etc), and that even if you don't need the black, then his purple power becomes deal 4k damage for 5 purple, which is insanely op. Just think about this - for 5 purple (which is 2 matches) you put 7 black on the board, which can crit and do cascades like crazy. It's ridiculously strong.
His attack tile is incredibly strong, especially against goons, and his green is good enough. Seriously, he's, imo, the best "support class" 3 star in the game. If you pair him with someone who has a good black power (BP, Luke Cage, Cyclops, etc) and someone who accelerates purple (Scarlet Witch being by far the superior option) and you've got a very, very strong team. It's that simple, really.