Queen Elsa & Merlin
Elsa and Merlin would be able to bond over having to hide their natures for much of their lives. Both grew up lonely and afraid of being found out, albeit for slightly different reasons. She, for fear of hurting her sister or other people, and him because of the anti-magic regime that would have had him killed. But together, they could benevolently rule Arendelle with their magical powers, and not need to hide anymore. Also they could be in love!