TheVaultDweller
Front line cannon fodder
Quinn and Sunny only fought once. And Quinn technically KO'd Sunny, who only managed to make a comeback because Quinn decided to go after Veil instead. He was out for a full 30 seconds while Quinn monologue'd to Veil.
Now, Sunny had already seen some action, so was definitely not 100%. But, at the same time, Quinn had a brain tumour larger than a golf ball at that point. And it was confirmed in one of his hallucination conversations with his dead son that he was still suffering from head pain. So, while Quinn was in better shape than Sunny for that fight, he also wasn't at his best.
I could still see Gaius winning though. Because, despite not having been around long, he's already racked up a bunch of impressive feats, like doing well against bloodlusted Castor, fodderizing several clippers, stomping his sister's regent. And all done after having spent over a year as a prisoner, living in crappy conditions.
Either way, I think it would be an awesome fight.