Psst. Psst. Hey @a-ard.
What about an X-Men/Marvel Arthurian legend AU where Polaris is the Green Knight?
As Green Knight, she’s sent by her sister Scarlet Witch (playing the role of Morgan le Fay) to test the X-Men (Camelot/Knights of the Round Table) and their leader, Cyclops (King Arthur). Professor X is, of course, Merlin.
Not sure who Gawain would be though. Maybe Jean Grey? It’d be kinda fun to see a scenario with a female character’s loyalty and chastity tested. :}