Darius A.k.a Nova

As a young child Darius was saved from Darkseid by none other than superman who didn't realize the kid had latent powers. over the years he grew into a fine hero learning his many powers such as flight, he can manipulate lightning and fire at will as supera strength and can move at high apeeds to name a few. He's not a Kryptonian however he has enough power to take up the mantle during Superman's absence. you are a hero he has teamed up with while not members of the justice league the both of you work closely with them (either gender is fine)