My heart says Black Adam with him being my second or third favorite DC character, but my brain says Gorr.
Black Adam didn't have a power upgrade or anything. He was just way, way, way more ferocious than anyone else and wasn't holding back at all. That's what made him so dangerous in that story. Martian Manhunter commented that Black Adam was facing people stronger / faster / more powerful than him, but that he still had the upper hand, because he was so ruthless. He wouldn't have that luxury against Gorr, who is stats wise also on a higher level. Dude withstood Mjolnir strikes, which shattered planets and nearby moons. I don't think Black Adam has ever faced that level of destructive power in all of his existence.