CW: Vampire!Luz, Momma Eda, Parent Raine, blood

So, in this AU, one of the only differences between the human realm and the Boiling Isles is what kind of demons you'll find. Boiling Isles is pretty much the same, but the human realm has vampires, warewolves, etc.
Also, vampirism is sort of like a curse if you don't know how to control it. (It takes over your mind and body, so you can't think clearly or control yourself)

And we're gonna say that Belos didn't exist in this AU, and Raine and Eda never broke up. Hunter does exist, but he's not a grimwalker. He's just a smol bean. Also also, just for funsies, Luz is an orphan

Long chapter

~~~

Luz looked up as eda came through the door with a bag of human things, like she did every week. "Guess what day it is!" She says, setting the bag down. As soon as she did that, a bat flew out, almost immediately flying over to Luz and biting her wrist.

"Ow! Why, you little-!" Luz complained, trying to shake the Bat off. Eda just incinerated the thing, and Luz grabbed the bite mark.
"You okay, kid?" Eda asked. "Yeah, I'm fine. I just really hope it wasn't rabid." Luz mumbled. Eda grabbed some bandages, wrapping the bite mark. "You'll be alright."

~~~

Later that evening, Eda had Raine over, and Luz was just chilling on the couch. To be honest, she felt.... Strange. Hot, but not sweating, and had the biggest headache.
Raine and Eda hadn't noticed anything until Luz groaned, putting her arm over her eyes. "Luz?" Eda prompted, looking over at her.

Luz didn't give much of a response, just a quiet groan. Raine looked over, frowning. "Are.. you okay, Luz?" They asked.
"I-i'm.. yeah, I'm just... Thirsty..." Luz mumbled, sitting up and putting a hand to her head. Everything was spinning; she felt like she was drugged.

"... Eda, s-something's wrong." She added, suddenly in physical distress. Before anyone could do or say anything in response, Luz's appearance changed rapidly as the sun went down.

Her eyes turned red, and her pupils constricted like a reptile's. She also grew fangs and bat wings, along with her nails turning into claws. She looked at Eda and Raine, not in control of herself at the moment, and hissed at them before flying out an open window.

"Luz!!" Eda called, in shock about what just happened. "Is.... Is she cursed?!" Raine asked, a bit terrified at what they just saw. Luz was fast.

"I don't know, this hasn't ever happened before!" Eda responded, panicking. "I.. I don't know what happened!"
"Well, come on, we have to find her." Raine said, getting up. "And do what? Raine, I've never seen this before!" Eda responded.

"I have an idea. Come on, we need to find her." Raine assured her.

~~~

Eventually, they did find Luz. She wasn't that far from the house, and she was hanging from her legs on a tree, with the bat wings curled around her.
Raine used their magic to basically lasso her down, causing Luz to get angry and try to either get away or attack. "I can't hold her for long, Eda. Give her this." They said, handing Eda a flask of red, slightly glowing liquid.

Eda decided to ask questions later, pouting the potion into Luz's mouth. After she drank it, Luz started reverting back to normal, and passed out. Eda held onto her, looking up at Raine. "What was that?"
"Blood potion. The beast keepers use them on carnivorous beasts to subdue them." Raine explained. "I don't know a lot about the human realm, but I do know that long ago, some of the demons from the Boiling Isles were banished to the human realm. One of those species were Blood Bats, or as humans call them, Vampires." They continued.

"But how did this-... Oh, no, it's my fault. This morning, I accidentally brought a bat back through the portal, and it bit Luz. That must have been what changed her." Eda realized, standing up and carrying Luz.
"You couldn't have known, Eda. Come on, let's get her back. She's going to be confused in the morning." Raine said.

"Wait, I don't... I don't want to freak her out with this yet. Maybe we should just tell her to take one of those potions every day, and tell her it's so she doesn't black out." Eda says. "... Eda, she's cursed. She should know what's going on."

"... Okay, but... Let's not go into detail about what her curse is, okay?.." Eda compromised. Raine sighs. "Alright.."

~~~

When Luz woke up, she had a headache, and her throat was dry. She realized she was sleeping on the couch, and Raine and Eda were talking quietly across the room.

"Eda..? What..." She said, her voice slightly hoarse. Eda and Raine looked over. "Luz! You're awake- so, kid... Listen. You got cursed-"

Before Eda could go on, Luz interrupted. "What?! I-i didn't hurt anyone, did I?!" She exclaimed. "Calm down, no one's hurt, not that we know of. But, you will need to start taking one of these every day." Raine says softly, handing Luz a vial of blood potion.

"It'll keep the curse at bay." Raine elaborated, before adding, "I'll teach Eda how to make them, so there's no chance you run out."
"But... I-i can't be cursed- Eda, I-" Luz started, taking the potion from Raine. "Kid, I promise it'll be alright, but you gotta calm down, okay?" Eda interrupted.

Luz nodded slightly, looking down at the potion. "When... Do I take this?" She asked. "If you start feeling really thirsty, or lightheaded, drink it. Those are warning signs of the curse surfacing." Raine told her.

Luz sighs, taking in everything for a moment. "Come on, you're gonna be late for school." Eda said after a moment. Luz nodded, and went to change for school, putting the potion in her bag.

~~~

"Hi Luz! Hey, did you get paler?" Gus greeted as Luz walked into school. Luz looked at her hands. "A little, I guess. I had... A busy night last night." She said.

~~~

Around lunch time, Luz started feeling dizzy. Remembering what Raine said, she excused herself and walked into the hallway outside the cafeteria. She took the potion out of her bag, praying to Titan it didn't taste horrible.

It did.

"Bleh! Ugh, I have to take one of these every day?..." She muttered to herself, then groaned. "One of what? What was that?" Hunter asked. Luz jumped, hiding the empty bottle. "Hunter!! It's not nice to spy on people, you know!"

"You're hiding something!" Hunter quipped back accusingly. "I am not-! Hey!" Luz shrieked as Hunter used his dash magic to swipe the bottle from her.
"Blood potion? Why were you..." Hunter trailed off. He was actually really smart, so he figured it out by himself. "Luz, did you get cursed?"

At that, Luz teared up. She'd been holding back a lot of emotions today. "Yeah, Eda and Raine told me that I need to take one of those every day now just so I can stay myself.. Hunter, I'm scared! I don't even know what kind of curse I have, and... I-i don't want to hurt anybody.."

Hunter thought for a moment. He was in the potions track, so he had a little bit of knowledge. "Well, blood potions are used for taming or calming carnivore demons and beasts. Whatever this curse of yours is-"

"Oh my Titan, I'm a vampire-" Luz realized. Hunter looked up at her. "That stupid bat!!-" she continued, rolling up her sleeve and taking off the bandages on her arm.
The bite had mostly healed, but it could still be seen. "Blood potion- ugh, I'm such a dunce, it was literally all laid out in front of me!"

"What's... A vampire?" Hunter asked. "Where I'm from... Well, I thought they were just a fairytale. But, vampires are demons that drink blood, and most of them used to be people." Luz explained.

"Sounds a lot like something I read; Blood bats were one of the creatures we sent to the human realm a long time ago, along with giraffes. Witches were getting tired of getting bitten by them, but apparently, when they bite humans, it changes them." Hunter recalled.

"Great, so I'm literally the only person in the Boiling Isles who can turn into this thing."

~~~

As the year went on, Luz got used to drinking her daily blood potions. She also, eventually, told the rest of her friends about the curse. They were all supportive, and said they'd do anything they could to help.

Today, though, Luz may have forgotten to take one. Which wouldn't be a problem, if she wasn't having a sleepover with Amity and Willow.

They were playing truth or dare, when Luz started feeling dizzy. "Oh no." She said, putting her hand to her head. "Amity, call Eda-" she managed to say before she started to turn.
Willow kept her inside with some vines, though even she struggled to hold Luz in this form. Amity called Eda frantically, explaining the situation.

"Eda, Luz turned, and I don't think she has a potion on her. We need you here, asap-" Amity started, though the call was cut when Luz escaped the vines, knocking over the crystal ball and flying on top of Amity.

Amity looked up at Luz, pinned to her own bed. She turned red, but was also worried about her girlfriend. "Luz, come on, snap out of it..."

Willow tried again to hold Luz with her plant magic, straining. Luz wasn't only faster in this form, she was stronger, too.

Eda showed up, having sped over once the call cut out. "Think fast!" She called to Amity, throwing her a blood potion. Amity caught it, opening it quickly and putting the bottle into Luz's mouth.

This was the first time Amity or Willow had seen Luz's curse.

Luz drank the potion, turning back to normal afterwards. This time, though, she stayed conscious. She groaned, jumping a little when Amity hugged her.
"Luz! Are you okay?!" She asked. "Y-yeah-... Are you? I didn't hurt you, did I..?" Luz asked, pulling back to look at her. Amity shook her head. "I'll be okay, Luz. I... I had no idea that's what you've been dealing with.."

~~~

A few weeks go by, until one day, Luz approached Raine (they started staying with Eda). "Raine? I... Is there any way I can control the curse? I don't want to keep being afraid of hurting someone.." she said.
Raine frowned a little. "I... I don't know. Beast keeping isn't my strong suit, Luz, I'm sorry.. but, maybe,... I might have an idea."

~~~

Raine had told Luz not to take a potion today, assuring her that they would have one if they needed. Eda was also out for a few days.

Sure enough, that night, Luz turned again. "Okay, Luz.." Raine started, wincing a bit as they cut their hand. "Let's do this."
The smell of Raine's blood drew vampire Luz over to them. Raine held their bleeding hand out to her. "That's it."

Luz grabbed Raine's hand, putting the wounded part up to her mouth. Raine winced a little; sure, Luz didn't bite them, but it still felt strange to have blood sucked out of you.
Once Luz's grip loosened, Raine pulled their hand back, watching her for a moment. Her form didn't change much, but when she opened her eyes, they were almost normal. Not reptilian, and not vibrant red. More like a very dark red that you could mistake for brown.

"I.. ah, why does it feel so weird to talk? And why-" Luz mumbled to herself, then saw her reflection. "Hoooolyyyy Titan-... Woah, I kinda look.... Cool-"

"It worked." Raine spoke up. Luz looked over at them, looking down at their hand. Because she was still in her vampire form, she could tell Raine was bleeding.
"D-did I hurt you-?!" She panicked. "No, Luz, you didn't. Don't worry about me, I'm okay." They assured her, smiling softly. "So, I have good news, and bad news.."

Luz sighs. "Always seems to be the case in the Boiling Isles." She mumbled. "The good news is, you can control it. The bad news... Uh, you need blood to do it."

Luz blinked, then rolled her eyes. "Of course. Why would it be anything else for a vampiric curse?" She asked rhetorically. After a moment, she hugged Raine.
"But... Thank you. I'm sorry this all happened in the first place, I... I didn't mean to become such a burden to everyone." She said, looking away.

Raine held Luz's shoulders, giving her a serious, yet gentle parental look. "Luz, you're not a burden. Just because you need a little bit of extra attention now, that doesn't make you a burden. You're my kid, okay? I'm going to do whatever I can to make sure you get what you need."

Luz teared up, smiling and hugging Raine again. "Thank you, Nibi Raine.."