Yes, I believe. He manipulate energy itself which means he can uses all sort of magics. And the facts that it already introduced to us that he can absorbs mana from outwardly, from air itself, means his actual mana pool=the world 🌎. And like he's also basically anti-magic in a world of magic. Once he reaches his full potential, he won't be needing the medallion to do it. But ehhh...if author don't wanted him to then he'll never be able to reach that level XD.
So theoretically he's one of the strongest. Not sure how fare he'll against something like time/space and reality manipulation though.
And maybe something like Cody just meant for support role you know? With his almost infinite many he can buffs Tate to be able to teleport simultaneously, Aiden able to clone more than 2 version of himself(Big Five Tiger), and Dallan Domain Expansion.
But then again, raw potential without the skill/experience/wit to wield it? Cody's nothing more than a battery for others to uses. Literally someone can kept him hostage and makes him ageless them uses him to power and charge stuffs.