Books like The Night Realm

Clio would love nothing more than to go home. But as the illegitimate daughter of the nymph king, she's stuck in the human world, exiled until she can earn a place in the royal family. Then her half-bother offers her a chance to prove herself. All she has to do is acquire some magic … by stealing it from the most dangerous spell weavers in the Underworld.Lyre prefers to go unnoticed, which is a tricky objective for an incubus. He can’t hide his looks or his coveted spell weaving skills, but he's learned to mask his true intentions. As an unwilling pawn of the tyrannical Hades family, he stays alive by keeping one step ahead of his masters.Now he's been assigned to watch over a visitor from the Overworld—one who's definitely hiding something. And with her unholy talent for triggering chaos and catastrophe, his job just keeps getting more perilous. Clearly, she'll never survive this world.The thing is, he's no longer sure he can survive it either.