answer:If you read the secret wars, the marvel heroes end up turning to Dr. Doom to assist them in fighting the Beyonder which results in a victory (for a while) Phoenix probably (as she has gone toe to toe with the Beyonder) I think we can safely add Hulk to the ranks of characters who can fight the Beyonder, eventually – as always – Hulk’s ever increasing strength would outmatch the Beyonder. I’d be willing to bet that the Void could lay some serious hurt on the Beyonder as well. And then there are those ethereal beings such as Eternity and his kin who surpass all within the Marvel Universe, there is no way the Beyonder can hope to go toe to toe with any of them. Outside of those characters… can’t think of anymore right now, and no one, NO ONE, say Captain Universe, that monstrosity of fiction doesn’t exist and never did.