God of Light Hal should have been a powerhouse, with a degree of reality warping and control (reconstructed Oa, the GL Corps and the Guardians without any of the parademons), but he also gave up the power early, so not much of feats to go by.
On the other hand, we've seen Thor hold his own ad defeat an amped Galactus and the Black Winter, universal level threats at minimum. That's a ery impressive resume.
Add the Thorforce and a revamped Mjolnir and its a wrap. GoL Hal would make it interesting, but Thor should take this mid difficulty.