Is Adam near Magus level? Did he master the Gem? If he's near Magus level I'm going to call it a stomp on Thor. If it's just gem mastery he puts up a fight but I call a 4/10. If it's just him with moderate control I say Thor stomps oh his neck and laughs.
Since we're talking about the gem, I'm assuming classic Adam.
Thor has more total power. Adam is a better tactician and very elusive. In a forum battle where we usually assume full use of power sets and whatnot, Thor wins. In a comic, Adam can and definitely would take some wins. Bear in mind his 'Him' incarnation was practically Thor's equal, and that was without all the guile and versatility of gem-Adam.
Yeah though blood in thunder thor just wrecked everyone he fought. He two-shotted surfer iirc. In most comics it would have been more even. But that showing does prove that he has the capacity to win, definitely. The only thing Warlock didn't try really was Soul Suck, and that's prohibited here so he'll lose most of the time.
I wonder if Thor would have been able to resist it. He was unharmed by his Soul Gem empowered Karmic Blast due to his fortified immortal soul. It would have been interesting to see.
Soul suck worked on a thanos clone which was just as immortal and the real thanos said it would work on him, so I think it would. I don't think power makes much of a difference, I mean it is an infinity gem after all.
Thor =/= Thanos. Just saying. His immortality has made him immune to various attacks and his soul has been shown to be incredibly powerful. I just think if one attack powered by the Soul Gem failed, it would have been interesting to see how Thor fared against Warlock's ultimate attack. I'm not saying he'd be immune. It is an Infinity Gem as you said.