#2 AEW star Sting

CM Punk was always interested in AEW star Darby Allin. In recent interviews, Punk has praised Allin:
"I think Darby Allin is great. Everybody in the wrestling world needs to never do a dive again because you can't do it better than Darby. If you watch Darby wrestle, he looks like he's trying to murder somebody. It doesn't get any better than that. Stop doing dives, everybody," said CM Punk. (H/T: Fightful)
The Voice of the Voiceless explicitly named Darby Allin on AEW Rampage as his first opponent and challenged the latter to a match at All Out.
With that said, it's highly improbable that he would get into a one-on-one match with Sting. While the two have never really crossed paths, them being in the same ring at the same time would be worth the price of admission.
Sting's recent performance on Dynamite in a Texas Tornado match was a sight to behold, and a welcome in-ring comeback. But given his age, The Icon's battle with a returning CM Punk would likely be restricted to a battle of wits on the mic.