Warnings: OOC, Demon Yuu goodness

I've recently become obsessed with Owari no Seraph, and wanted to try writing a fic.

I'm also obsessed with Demon Yuu and Salt King fanfictions, and there doesn't seem to be many, so I wanted to contribute some.

Also, I haven't read much of the manga, only watched the anime, so I'm not too clear on everything demon Yuu related. Just my own interpretation.

"Yuu-chan..." Mika whispered.

Yuu had turned into a demon again. It lasted a little longer this time, as it had been doing lately. It's already been twenty minutes since he was supposed to change back. Mika wondered how long this would last.

"Mika, I know you're there." Yuu-chan, no, this wasn't Yuu, the demon said.

Mika walked out from the shadows, facing the demon. "You're not gone yet." He stated.

The demon smirked. "What's the rush? You don't like me very much, do you Mika? Mm, that's a shame. I thought we could have a little fun~."

"Don't make things like that come out of Yuu-chan's mouth." Mika growled.

"I'm sorry, if I'm here things like that are going to be said. Why are you so grumpy, Mika~? Are you hungry?"

"No." Mika said coldly. It didn't matter if he was or wasn't, he wasn't going to drink from the demon. The only person he drank directly from was Yuu-chan, and he didn't even do that all the time. He tried not to drink form his best friend as much as he could.

"Yes, you are. I can tell. Drink my blood, vampire."

"Let me guess, I drink your blood in exchange for letting you out?"

"No. Just let me take care of you." The demon said in a sickeningly sweet tone.

Mika scoffed. He wouldn't let this demon deceive him. He clearly wanted something, or had an escape plan that he would put into action as soon as Mika opened the cell or had his guard down while drinking his blood.

"I know you want something." Mika said.

"I really just want to take care of you, Mika. Yuu notices when you don't get enough blood. When was the last time you drank? A week? Maybe two?"

A week and four days, but Mika didn't want to drink from Yuu constantly.

"I'm not drinking from you, demon. Just release Yuu-chan."

"You're not getting rid of me."

That made Mika somewhat afraid. What did he mean he wasn't getting rid of him? Eventually, Yuu-chan would come back, wouldn't he? He always did. Mika believed in him. No matter how long it took, Yuu-chan always made his way back to him. He wouldn't be deceived by this demon's words.

Silence washed over them. For the next hour, no one said anything. An hour turned into two hours, then three, and then Mika started to wonder if there was truth to the demon's words.

"You're not getting rid of me."

Was he really never going to see Yuu-chan again? It had never taken this long. Even when the time Yuu was an demon increased, it never did by this much. Ten minutes at most, maybe fifteen. Never an hour, most certainty not three.

When it had almost been four hours since Yuu-chan should've turned back, Mika asked,

"Why haven't you changed back yet?"

"I told you, you weren't getting rid of me."

"What do you want?"

"I want you to drink my blood."

"And let you out?"

"No. After that, I'll leave."

Mika shouldn't trust the demon's words. He really shouldn't. But he was started to get worried that he'd never see Yuu-chan again. So he asked,

"Why? What's in it for you?"

"Believe it or not, I want to take care of you, Mika. Yuu-chan is always the one that gets to do it. Every time we see each other, every time I'm here, I'm always chained up to this wall. It's kind of boring, don't you agree? I wanted something a little more exciting, can you at least give me that? I promise I won't run away. If I do I give you permission to subdue me."

"I don't need your permission for that." Mika spat.

"Is it a deal?"

Someone really should've told Mika that you should never make a deal with a demon, no matter how much they looked like your best friend.

"...Alright." Mika agreed.

If this was the only way to get Yuu-chan back, then he'd do it. He wouldn't un-chain his wrist, so there's no way the demon could get out. And if he did, Mika would just subdue him.

Mika unlocked the cell, walked in and sat in front of Yuu-chan, no, the demon. "Are you ready? You going to bite me, Mika?" "Don't speak." Mika growled. The demon chuckled. "Right. Not another word."

Mika took Yuu's shoulders into his hands and bit the demon.

"Ah..."

The blood...the taste was the same as Yuu-chan's, savory and slightly salty. The most delicious thing he's ever tasted. Mika wanted more. "Drink as much as you want." Yuu-chan whispered to him. Mika continued to drink, moving his hands from Yuu's shoulders to wrap around his waist. Then Yuu's arms were around Mika, one around his waist while the other was on his head, stroking his hair like he always does when Mika drinks his blood.

"As much as you want..." Yuu whispered to him again, somewhat seductively. Something felt wrong about it. Yuu-chan doesn't talk like that, not his Yuu-chan. Yuu-chan doesn't say things like this when he drinks from him, only tells him comforting words and whispers of "It's okay."

This wasn't Yuu-chan.

Mika immediately pulled back. What had he just allowed himself to do? How much of Yuu's blood did he drink? How had the demon broken free? It's your fault! Mika wanted to say to the demon, except it wasn't. Mika should've never listen to him. Yuu would've come back eventually. He always does. Now when he comes back he'll be disappointed in Mika. He might even realize what a monster he was, drinking from a demon, draining to much blood from Yuu. What if Yuu isn't okay when he comes back? What if gets sick? What if-

"You're no fun, you stop too fast and then you get that look on your face like you got caught stealing the last cookie."

"Shut up!" Mika yelled, pressing the demon against the wall in anger.

"Feisty, I like it." The demon said, leaning his face closer to Mika. Mika could feel Yuu's breath on his face.

"Well? Are you going to do something? I'm still here, Mika~ Your precious Yuu-chan hasn't come back yet. You can still punish me if you want."

"Don't...don't talk about him!"

"In essence, I'm kind of talking about myself. I am him after all. Or at the very least, we share the same body."

They do, and anything he did to this demon Yuu-chan would feel later. Mika immediately loosened his grip on the demon's shoulders. "Really? Stopping again so fast? You really are no fun."

What did this demon want? He hadn't run away yet, like Mika thought he would. Was that because he was distracted? Mika would just have to keep him distracted, then.

"What do you expect me to do?" He asked.

"I don't know, something like this, maybe?" The demon said, pushing Mika onto the hard floor and pinning him down. "And then, I wanted you to drink for this long." The demon said, piercing him with his fangs.

"Ahh..!"

He didn't expect the demon biting him to feel like this...this good. There'd been the initial pain, but then all he felt was pleasure. Was this because this was his Yuu-chan? Was there really some small part of that demon that was his Yuu-chan? And, was this how Yuu felt all the time when Mika was drinking his blood? Because this felt so good...

The demon paused in drinking to whisper, "You want more, don't you?"

Mika couldn't help but nod.

"Yuu-chan..." Mika breathed out, wrapping his arms around him.

All too quickly Yuu pulled away. Mika felt dizzy afterword. "That's how long you should've drank from me, vampire. Next time, that's what you'll do." Yuu ordered him...no, this was the demon. Mika was getting more and more confused. There was still some of Yuu in this demon, so...is this what Yuu secretly wanted him to do?

Suddenly Yuu's body went rigid, his fangs and horns receding and his eyes returning to their normal beautiful green color. "M-Mika! What happened?! Did I hurt you?! I hurt you, didn't I?" With Yuu pinning him down and Mika's bleeding neck, it probably looked something like that...

Mika wasn't sure how to explain it.

"No, um, Yuu-chan. You didn't." Mika said. "Then why are you bleeding?" Yuu asked, getting off of him and helping him sit up. The world spun around when he did, and Mika tried to focus. "What happened?" Yuu asked. "You didn't hurt me, Yuu-chan...It's my fault...I thought...I had to the stupid idea to...I thought that...I...I thought..."

"Mika!" Yuu said, steadying a swaying Mika. "I-I'm sorry." Mika mumbled. "Why are you apologizing? I'm the one that did this to you, aren't I? Drink my blood." "I-I already did too much." Yuu tightened his hold around Mika to keep him from falling. "But I bit you too, didn't I? I didn't know I could drink blood. The bite marks are from me, right?" Mika weekly nodded. "But I bit you first..." "I told you that you could anytime. I'm sorry I bit you. Probably without asking." "No, Yuu-chan..." I enjoyed it. I didn't stop you. Mika wanted to say. He wasn't sure how much of it he should. Instead he kept quiet, biting his lip nervously. Would Yuu-chan be mad at him when he found out? That all of this was his fault?

"Mika, drink my blood. Before you pass out." It was true, he did feel incredibly tired...he really just wanted to rest. But Yuu-chan would probably be even more worried if he passed out, so he scooted himself even closer to the black-haired boy and drank his blood.

"Ahh..." He made the same sort of noise as last time. Did it really feel good when Mika drank his blood?

Soon enough, Mika stopped drinking. He only drank enough to regain his strength, nothing more then he needed this time. He wouldn't drink more then necessary again. "I'm sorry, Yuu-chan..." He whispered, looking down at the floor. Anywhere but Yuu-chan. Yuu lifted Mika's face up to look at him, cupping his cheeks. "You didn't do anything wrong, Mika. I'm sorry for what I did to you. Are you okay now? Does it still hurt?" It didn't hurt, not at all. He should just tell Yuu-chan the turth. Sure, he would be angry and disappointed with Mika, but it was better then Yuu-chan feeling guilty. He didn't want him to feel like Mika did right now.

"No, Yuu-chan...It's not your fault. I bit you. And drank more than necessary. I came in here and let you break out of the chains. And then when you bit me, I didn't stop you, I..." Mika face turned red in embarrassment. "I enjoyed it, so I didn't stop you. It's my fault."

"Oh..." Yuu said. This was it. After he had a moment to take everything he said in, he'd be furious with Mika. "That's okay." Mika flinched, not expecting him to say that. He'd already been anticipating that Yuu would yell at him. He didn't think he'd be okay with it. "It's okay, Mika."

"Yuu-chan...It's not. It's my fault." "No, it's not. To best honest..." Yuu paused, blushing himself, not looking at Mika anymore. Mika found the bashfulness cute. "It feels good when you drink my blood, too. I understand not wanting it to stop. And we're both okay. So it's okay." Mika felt relived that Yuu-chan wasn't mad at him. That he understood.

"You can have my blood anytime. Though next time we should make sure I can't break out of the chains." Yuu told him. "You can have my blood anytime, too." Mika told him. It was only fair, really. "That probably isn't a good idea. I don't need blood, and you were on the brink of collapsing before because of me. Don't let me drink your blood, okay?"

Mika couldn't promise that he wouldn't let the demon next time if he asked.