If he did it agaisnt Eru's will, Eru isn't omnipotent. If he did it with Eru's will, these aren't his feats.
And who says is either of that true?
Eru created someone strong enough to go against an omnipotent, but no change took place in himself. infinitely greater than odin.
Even if he did it with eru's will, everything odin, thor, hulk, or literally every character of marvel does is becauseof toaa's/writer's will. If we discard the omnipotent's will, we have two entirely featless characters, making the thread pointless. And I'm sure op did not mean that.