Adam Cole has never been good, and he is particularly bad now. It's really weird that TK got so many 2019-21 NXT talents - and feuds! - to AEW and made them central to his booking....after two years of kicking their ass so badly that they did an entire revamp of the show.
Trying to think of ex-WWE hires (made after AEW was already established, so between 2020-present) who have actually made a difference for the better. I won't include Punk in this because while he is "ex-WWE", it's a unique set of circumstances. Dragon has been a huge, unqualified positive. Swerve is awesome, and he grabbed the opportunity with both hands and showed us all that he isn't just a good wrestler, but also a tremendous promo, and his charisma has really shined through and gone to the next level in the last year, taking him along to the next level as well. And although a section of fans don't like them, I think FTR has also overall been an excellent addition to the company, not just in the tag division, but also as part of alliances feuding with and wrestling other such alliances. I am a massive Mercedes fan, but she has been quite spotty, with some very good stuff mixed with some boring/bad angles.
Christian has been tremendous in certain angles and stories, but is now losing his effect due to repetitive, predictable, uninspired booking and storylines.
Which other ex-WWE hire made after AEW was already established as a legit major-league national promotion has made a proper positive impact?