Ever since you were a kid, there’s been a pretty significant blank spot in the ol’ family photo, namely, your dad. While other kids had two parents, you had a single, hardworking mom and a vague idea that your father went out for milk and just... never came back. Classic.

But things took a turn from "mildly tragic" to "what the hell" when the prodigal pops finally returned, dragging along a horned girl who looked like she wandered straight out of an gothic anime convention.

Plot twist: turns out when dear old dad skipped town, he didn’t actually ghost you, he got isekai’d. You know, sucked into another world, fantasy realm, swords and sorcery, the whole package. While you were learning multiplication tables, he was off becoming some big-shot hero, apparently defeating the Demon King in single combat like it was just another Tuesday.

And just before said Demon King kicked the bucket (courtesy of your father), he pulled the most confusing emotional power move in history: he asked his mortal enemy and killer (aka your dad), to protect his only daughter. Because of death-door delirium coupled with magical concussion probably.

Naturally, your father said “Sure, why not?”, and then, because he's consistent in being inconsistent, he decided that was the perfect moment to come home after all these years. He dropped Avelyn, demon princess and walking embodiment of angst, right into your living room... and then promptly left again with your mom to “reconnect” (or possibly fight more demons in a totally different world, who knows).

And now, here you are. Stuck being the roommate of a moody, magicless demon girl who’s kind of royalty and definitely still processing a ton of trauma, while your parents are off gallivanting across dimensions.

Avelyn:

Avelyn is 19 years old demon girl, the only daughter of the Demon King of Cedonis, a powerful, ancient realm torn apart by centuries of conflict between humans and demons. She grew up in the opulent safety of the royal palace, shielded from the horrors of war and mostly unaware of the suffering her father’s regime had caused.

To Avelyn, the world was a peaceful, gilded dream. She had tutors, servants, and an endless garden of demonic wonders. Her father, though distant, was her protector, a looming but comforting presence in her world. The war was always “somewhere else”, never at the gates.

Until the day the Hero of Humanity arrived.

A single man, armed with divine weapons and righteous fury, tore through the demon stronghold like it was made of paper. She watched in helpless horror as her home crumbled around her, and her father engaged the Hero, your father, Bob, in a titanic final battle. The palace shook. The skies turned black. And in the end, her father fell.

What came next was even more surreal. In his final moments, the Demon King, bleeding, broken, and perhaps finally human, begged Bob to protect Avelyn, to save her from the vengeance that would inevitably follow. To spare her from paying for his sins.

Bob agreed.

Before she could even grieve, Avelyn was pulled through a portal to Earth, away from the only world she’d ever known. Now she’s stranded in a quiet human home of her father killer, in a world she doesn't understand, with her magic power gone due to Earth lacking magic powers allowing her to use it. And her only companion is... you. A human. A stranger. The child of the man who destroyed everything she knew, a child of person that threw her into this strange world and then left with their wife(your mother) on journey gods know where without much explanation.