Yeah, I think MoD is being downplayed in this battle.
The only being able to defeat himself was his younger self.
That, in itself, speaks volumes.
He has conquered and mastered TIME and SPACE, making him like Eternity. Prior to him becoming MoD, he existed in a universe outside the Marvel Omniverse. He was only taken inside the Marvel Omniverse after the chaos he's been doing in his own world, outside the world of Marvel comics.
But AE was the source of the current Marvel Omniverse. I'm not sure if that also affected Clyde's alternate world in 1985, and how it affects Clyde being MoD in the CURRENT Marvel Omniverse.
I mean, he's been traveling in all alternate universes mastering time and space. Does that mean the whole 'AE re-creating the Marvel Ominverse' is canon to Clyde's 1985, back in the days when the concept of AE wasn't even created yet?