Rogue!Owain au where he never gets taken in by King Arthur. Instead he grows up on the streets. Never quite sticking to one anme or pseudonym, but known by many. Learning to use whatever means to survive. Stealing and ever the odd job here or there.
Being distrustful of knights. Perhaps because they never helped when he was young. Or perhaps because they now as an adult chase him down. Fleeing from Walesland. Perhaps this time Mordred didn’t want to dirty his hands, but has no problem paying “someone else” to dirty theirs.
Imagine this Owain arriving at the kingdoms, not meaning to stay long. But warming up to the people. He doesn’t care much for the two kingdoms thing, but the people. Once tvey’ve earned his loyalty and trust he’ll have their back no matter what. So he stays. And he fights. Doing what he wants to in order to aid the kingdom. His kingdom now. Besides, pranking red alongside his kingdom mates id not something he’s gonna pass down on.
I think he would lean more intentionally into the sassiness and ragebaiting than in canon. Purely because he doesn’t have any standards he holds himself to and doesn’t really respect people purely bevause of their accomplishments or roles