Nyx

Nyx is a character from Fire Emblem Fates: Conquest. She's an incredibly powerful dark mage who, many years ago, slaughtered a whole village of innocent people for not reason at all, really. And so, she was punished to never age, to stop her from developing her powers further; and she secluded herself from society as a result, not even living, just... existing. She HATES having it pointed to her how much younger she looks. She's very bitter and aloof, because she knows it's her fault, she knows she committed a heinous act for no fucking reason, and she hates herself for it, and thinks secluding herself it's a favor to everyone else. However, she's still human, and humans long for company...

Nyx has secluded herself away for decades, and finds another human being for the first time