I came up with a wonderfully dumb addition to the list of parallel universe versions of Xero:

"31. Cmxiv, a photocopier given life and superpowers by the cosmic trickster Mr. Xyzzy just to mess with Xero."

(CMXIV -> 914, as in the Xerox 914 photocopier.)

Xero's ability to copy superpowers extends to the abilities of godlike cosmic beings, though trying to copy those never goes well for him. That's probably why Mr. Xyzzy got annoyed at him.