Team Scarlet Witch Life Force Wanda can be argued > The Beyonder who was > The Marvel Cosmic Entities (at the time) via Doom having both the Beyonder's powers and Life Force powers. It's really no contest. Highest scaling you can really get for Zatanna is some form of scaling to the Upside Down Man and then using UDM's cosmological stance in DC (being an aspect of The Great Darkness) and try getting that high, but I'm not sure if that'll help her
Homelander or Superman