Alastor x younger sister! Reader
Summary: Alastor had been assured for years that the only two good things from his life, his mother and little sister, were safe in Heaven. But what happens when he finds one of them in Hell?
Warnings: Mentions of abuse in a foster care system, cuss words, etc. PG-12. You are in charge of your own media consumption.
Requested by @rosearts414
Alastor never spoke of his family, and for good reason. His time alive was filled with pain, both some he caused and much he felt. The only lights in his life were his mother and little sister, and for centuries, he had clung to the comforting belief that both had ascended to Heaven and were spared from the torment of Hell. It was the only sliver of peace he allowed himself, that his sweet, innocent kin would never know the corruption of the damned. That illusion crumbled the moment he spotted a small fawn darting nervously down a cracked street in Pentagram City. The creature froze when it noticed him, ears flicking and slowly beginning to turn away. Her tiny hooves tapped hurriedly against the cracked pavement. At first, he thought nothing of it. Just another damned child at play. But that all shattered when the fawn paused to peek back and meet his gaze, large innocent eyes blinking up, and in an instant, memories long buried surged within him.
Alastor’s grin faltered for the first time in centuries. There was something achingly familiar in the way she tilted her head, something that tugged at long-buried memories. A child’s laughter. A little girl tugging at his sleeve. The sound of her calling him 'Allie' because his full name was too long for her small tongue. It hit him like a thunderclap. This wasn’t just any fawn. This was Y/N...his little sister.
The fawn blinked, taking a hesitant step closer. Her voice, soft and unsure, broke the silence. “...Allie?”
Alastor let out a strange, almost breathless laugh as he crouched low, his cane resting against the cobblestone. “Oh, why yes, it is now!” He started to reach out but contained himself and plastered the grin right back on his face.. “And you are still so small… still my little one.”
The fawn pressed up gently into his side, testing, as though making sure he was real. His grin softened into something genuine, fragile, tender in a way none of Hell had ever seen from him. He paused before stroking between her ears with care, voice dropping lower. How was she here in this hellish place? She was so small, so innocent, so unlike him. He hadn’t meant to die when he got shot by that hunter, but when he did take his last breath, he was sure she would be okay.
When he carried her to the Hazbin Hotel, the reaction was immediate. Charlie’s eyes lit up with wonder, her hands clasping together. “Oh my gosh! She’s adorable!” Vaggie followed close behind, protective but intrigued, while Angel Dust leaned lazily against the wall. “Well, well. Didn’t know the Radio Demon had a kid tucked away somewhere.”
Alastor’s smile sharpened. “This is Y/N. She is under my protection, and anyone who dares so much as look at her the wrong way will regret it.” His tone held such a dangerous edge that even Husk flicked an ear uneasily.
Y/N peeked shyly from behind his leg. Charlie knelt down, her smile warm and reassuring. “Hi, sweetheart. Don’t worry, you’re safe here. We’ll all look after you.”
Alastor’s laugh was light, but his crimson eyes never wavered from the others. “Oh, I shall see to that personally. Her safety is mine to guarantee. Do we all understand?”
The static under his words left no room for argument. Angel raised his hands in mock surrender and stepped back with a muttered, “Yeesh, touchy.”
In the days that followed, Alastor scarcely left her side. He took her out to the hotel’s little garden, humming jaunty jazz tunes as she nibbled happily at the grass and flowers. When she was tired, he scooped her into his arms with ease, striding back into the hotel with an unmistakable pride in his step.
Husk caught sight of them once, Y/N curled up asleep against Alastor’s chest, her small body rising and falling with steady breaths. “Never pegged you for the dad type,” Husk grunted, taking another swig from a cheap bottle. After so long under Alastor’s command, he had lost all sense of pretense with the Radio Demon.
Alastor adjusted his bowtie with his free hand, grin unwavering. “Oh, Husk…”
Alastor paused; no quippy or deflecting remark came out. Only a painful flash of memory and screams. Y/N had told him late one night that, soon after his own death, she was placed in a foster system. Her "new" father, a complete drunkard, had killed her in a blind rage. The story alone made his blood boil, and he would sooner find that wretched bastard down here and make him pay if it wasn't for the fact that he had to console Y/N after telling her story.
“It is… fulfillment of a promise. I vowed to protect her once, and I failed. But now…” His voice darkened as he looked down at her. “Now I have the chance to make amends.”
Husk wasn’t the only one who noticed Alastor’s strange change in behavior. Charlie, though exceedingly trusting of the deer demon, knew him not to be one who expressed much affection. One evening, she peeked into the lounge and saw Alastor crouched low, one hand extended as he guided Y/N’s clumsy steps in a little dance. His voice carried a playful rhythm as he hummed, encouraging her to twirl.
“Yes, yes, that’s it! A perfect spin, you make quite the lady.” He clapped his hands with genuine delight when she managed it.
Charlie leaned against the doorframe, whispering to Vaggie, “I’ve never seen him like this before… It’s almost sweet.”
Vaggie folded her arms, though her lips quirked. “Guess even the worst monsters have soft spots.”
Angel Dust smirked from the corner. “Yeah, but don’t tell him that. Guy’s scarier than ever in brother-bear mode.”
Maybe Angel was right. But for Alastor, Hell had always been a stage, somewhere to perform, to grin, to play games and win it all. But with Y/N, it became something else. With Y/N, it finally felt like home. And that scared him more than anything.
This moment where Sir Kay thinks he's dying and one of the last things he mentions is "my worshipful wife, who never angered me." It's obvious as hell that he loves his wife so damn much. 🥹
