Joey Janela
A lot of the choices for potential feuds for Moxley will be much different than ones he had in WWE. The TV-14 rating suits his character better than TV-PG and there are several other characters in AEW that are better suited for the mature rating. One such man is 'Bad Boy' Joey Janela.
I've always thought he looked like a shorter version of Dalton Castle but flanked by Penelope Ford rather than the Boys. But unlike Castle, Janela takes part in more hardcore matches than 'the Party Peacock'.
Since both Janela and Moxley are not strangers to bleeding or having matches with weapons or tables, it makes sense for the two men to eventually cross paths in AEW. The alignments wouldn't matter because both men would be cheered regardless of if they are heels or faces.
It could be a hardcore-based feud like Moxley's old days in Combat Zone Wrestling or they could clean it up a bit with AEW's deep pockets. All Elite Wrestling showed us that it will incorporate a little more blood (Cody vs. Dustin) and foreign objects (Jimmy Havoc's staple gun) than WWE, and this is a feud that would fit in perfectly with those new facets.