metagross would win but i support tyranitar cause i prefer him over metagross
but in reality metagross could take tyraintar down with hammer arm X4 damage to tyranitar.
Even tho tyranitar is immuned to psychic metagross doesn't fear darks because
so it it doesnt have any dark weakness.
if you can get a sneaky earthquake in you might have a chance but still metagross is supirior is speed and attack its just i prefer tyrnaitar...