Suggested by Destroyer Now this is a close fight that I went back and forth on a bit. One Above All is old but Arthur’s very young. Can a kid beat an old man? It really comes down to that. Arthur has thrown a punch before but it wasn’t all that powerful. Ultimately, I guess youth would win this. I think the One Above All is just a little too old and that will come back to bite him. Arthur wins.
DReager1.com 
Please do Merlin the Magician from The Magic Treehouse books next!
Merlin eh? Who do you want him to fight?
Whatever has Arthur done to deserve fighting against a being infinite in power?
Arthur has fundamental strengths though which the One Above All is still lacking