I had an idea that could be discussed. By no means set in stone. A twist on the whole 'from two worlds' theme but rather than the King to Peasant or two opposing cultures I had a thought to mix science fiction and fantasy.
Where a man from a sci fi based universe through a magical event meets a women from a world ruled by magic.(Perhaps she fumbled an untested spell or the moons aligned?) Then they learn of each other's worlds as she explores his galaxy and later he is just as confused when he visits her magical world to return her home. While this occurs they would be fighting off threats from each others universes, such as space pirates, hostile aliens, evil warlocks, orcs on a warpath ect. I would play the man from sci fi and the character's history, occupations nor abilities are not set. For example the man could be a space smuggler, alien, space marine ect And the Maiden could be anything from a witch to a fairy or perhaps a Vampire. Anything mystical or magical.
Just shooting an idea to hopefully start some discussion and interest.