To say that Master Pandemonium is sort of a weird supervillain is like saying a live hedgehog is sort of a bad form of birth control. How does having baby arms -- not baby arms as in Deadpool growing back his missing hand, mind you, but baby arms as in actual babies for arms -- make him "unbeatable" as he claims above? What's his signature move, smacking you with a red-headed stepchild? Can he even feed himself, or does every hot dog he picks up from a street vendor hilariously disappear a la Bugs Bunny's carrot before it reaches his lips?
Of course, it's possible that Monsieur Pandemonium was referring to an altogether different connotation of "unbeatable." After all, the man can't even soap up his taint in the shower without facing 25-to-life and a yearly check-in with the sex offender registry.
Sure, we could explain in depth the backstory there, try to put it into some sort of context. We just choose not to. That would ruin it.