So in the Tam Lin story, the heroine had to hold on to her lover while the Queen of the fairies turned him into a ton of dangerous beasts. If she held on, Tam was hers, and free of the Queen's grasp.

So let's say Ardyn kidnaps Noctis and does some handwavey magic on him to make him daemonic. In order to bring him back to his mortal form, his lover has to hold him through the first few hours of dawn. he shape shifts into various daemons during that time, as the magic slowly leaves his body.

I'm fine with any ship, tho any of the chocobros or Luna are favored. And if you want to go the Tam Lin route where the lover is pregnant, eyyyy that's a ok, friend.