#2. The Young Bucks
Another great way to knock the ring rust off of all while doing a big-time match with him could be to pair him with a partner to take on The Young Bucks, who are by far going to be AEW's biggest tag team when the company officially launches. In fact, after the launch, the team might end up being the biggest tag team in the entire business.
When Punk appeared on Colt Cabana's Art of Wrestling podcast in November of 2014, he somewhat sarcastically mentioned that he'd come back to work against The Young Bucks, so even though he might not have been completely serious when he said it, there's probably a part of him that does want to work against the team.
As for who Punk's partner would be, well, that's a little tougher to figure out, as there aren't a lot of guys in the company who have strong ties to the ex-WWE Champion. Also, pairing him with another ex-WWE guy might not be the best move unless AEW wants to bring Punk in as a heel, which wouldn't make any sense at all.