Genre fiction has many explorations of romantic love between an immortal being and a human protagonist – vampire stories are especially good for it. What’s less common is a focus on familial love between someone who’s fated to live forever, or at least several centuries more than most, and a human who won’t be alive for nearly as long.
Maquiaisn’t about vampires (and it’s not a horror), but does follow the parent and child relationship between a woman of fantastic origin and the mortal boy she takes under her wing…