Defeat Rune King Thor with the Infinity Gauntlet.

With Rune King Thor's omniscience, would anything be able to challenge him if he had the Infinity Gauntlet?

Rules.

Battle takes place in the universe that Rune King Thor resides in.

Beyonder Doom

Any Beyonder.
Possibly an Infinite, one of them manhandled Eternity like Thanos did with the HotU.

Strange Visitor Superman.

Originally posted by Zack M
Strange Visitor Superman.

Agreed

Classic IG could do it easy , but that was before they Nerfed it for some reason.

Has anyone considered RK Thor's Omniscience coupled with that gauntlet?

The IG grants omniscience anyway.

Franklin richards defeated the mad celestials who defeated three reed richards with the three infinity gauntlets...

Franklin wins