You were in a dream of some sort the only thing you could see was an endless void with a giant black hole in the sky.

Y/n: What the hell?

You started walking forward but no matter how far you walked it got you nowhere. What felt like minutes of walking you decided to stop realizing your not going anywhere. You then felt a presence behind you turning around you see a girl with hair like Rias but her eye color is pink.

Y/n: Hello?

You see her lips moving but no sound comes out. You decided to walk a bit closer to her.

Y/n: Soooo. Do you know where I am?

Again her lips move but no sound comes out.

Y/n: Right I can't hear you or your just mute. Or maybe I'm deaf.

Then the ground started to shake violently. A roar could be heard. Looking up you see something flying heading your way at an insane speed before you know it the figure lands in front of you revealing to be a Dragon it's scales are black it stares at you with its eyes.

Y/n: A dragon.

You stood there shocked. Just then the girl that was behind you came to your side and cups your face with her hands. She stares at you and she speaks.

???: Come find me Y/n.

With that you viciously sat up from your bed waking up from your slumber you were drenched in sweat. You looked around and noticed you were in your room. You got up and sat on the edge of your bed.

Y/n: What the hell was that? A dream? Or something else.

You heard the sound of running and next thing you know Yui burst open your door wearing her amour.

Yui: Y/N! We have a problem!

You instantly stood up from your bed.

Y/n: What? What's wrong?

Yui: They just came out of nowhere!

You walked over to Yui and put your hands on her shoulders.

Y/n: Your not making any sense. Just take a minute to breathe and relax.

Yui: Okay.

She took deep breaths trying to calm herself down a few seconds has passed her breathing seems to have slowed down.

Y/n: Okay. Now tell me what's going on?

Yui: Demons.

You looked at her suprised.

Y/n: What do you mean Demons? How many?

Yui: I don't know. Everything was normal then all of a sudden I detected a large amount of demons in the area.

You let go of her shoulders and walked over to your dresser and pulled out blue Jean's and a white shirt. You put them and reached over to your bed a grabbed your scarf.

Y/n: Alright we got some demons to take care of.

You walked over to your window and opened but before you could jump out Yui called out for you.

Yui: Y/n. Wait.

Turning around to face her you gave her a confused look. She held out her index finger telling you to wait a moment she left your room in a hurry. A few seconds later she came back carrying a box.

Y/n: What's this?

Yui walked over to your bed and placed the box on it.

Yui: This belonged to my brother he was a good person. I want you to have it.

Curious you walked over and opened the box and saw an outfit in it.

Y/n: Yui I can't take this.

Yui: You can and you will.

Y/n: But isn't this something that swordsmen wear?

Yui: Who says you to be a swordsman to wear it?

You just stared at the outfit in silence.

Yui: I'll go on ahead come find me when your done getting dressed.

She walked over to your open window and jumped. Leaving you alone in your room. You walked away from your bed and to your window. You were about to jump out but looked back at the box.

Y/n:*Sigh* Might as well.

Walking back over to your bed you picked up the outfit.

(Timeskip)

Yui was standing on a roof scouting out the area keeping an eye out of Demons. Hearing something behind her she quickly turned around her hand on her sword. Standing a couple feet away from her was you wearing the outfit she gave you

Yui then let out a sigh of relief and quickly smiled at you.

Yui: Don't you look good in that.

Y/n: It'll take some getting used to but it's not a bad look.

Yui then set her eyes on your scarf that was around your neck.

Yui: Why do you always wear that scarf? You've had since I first saw you. The only time you take it off is when you sleep.

You touched the scarf around your neck clutching it.

Y/n: My father gave it to me I ain't ever getting rid of it.

Just then you caught multiple foul scents.

Y/n: I can smell them.

Yui: Do you know where their at?

Y/n: Yeah I do.

You point over to an abandoned warehouse.

Yui: Do you know how many?

Y/n: Hard to tell they're all in one spot. But I do smell a strong scent probably their leader or something.

She looked over at the warehouse she put her hand under her chin.

Yui: I say we take them by suprise so we need to be absolutely quiet about this.

She turned her head over to the spot were you standing only to see you were gone.

Yui: Huh?

She looked over at the warehouse and saw you jumping from roof to roof making your way to it.

Yui: Or we can do it your way.

She started jumping from roof to roof following you.

You stopped at the doors the demons scents can be smelled on the other side. You heard something softly land right behind you turning around you saw Yui who finally caught up with you.

Yui: Y/n we need a plan.

Y/n: I have one. Kick demon ass.

With that you raised your leg kicking the door down. You begun walking inside Yui following closely behind. Both of you were on high alert.

Yui: Smell anything?

Y/n: Yeah it's like their everywhere, this whole room practically stinks of demons.

Just then something drops on your shoulder. You grab whatever it was and see it's a chunk of meat. Then it hits you it's not any meat, its human flesh. You slowly look up and saw an unknown amount of demons hanging from the ceiling they all look at you and scream alerting the other ones inside the warehouse. They all dropped down swarming you and Yui as the two of you went back to back. You then got a better look of the demons.

Y/n: Okay. That has to be the most disgusting and disturbing thing I have ever laid eyes on.

Yui: Normally these types of demons are weak. But they become a big problem when there's a swarm of them!

Y/n: So what's the game plan.

Yui: You already forgot.

She drew her blade getting into a stance.

Yui: Kick demon ass!

With that Yui charged them swinging her sword horizontally getting multiple demons in half.

Y/n: Okay then.

You turned to the group of demons in front of you. One of the demons charges you it jumps in the air bringing its arms down on you. You quickly uppercut it making it hit the roof.

Y/n: Anyone else?

Then they all started charging you. Cracking your knuckles you charged them as well. You dropped kicked one of them sending it backwards as it hits the demons behind it. Lightning engulfed your right arm is you hit one of the demons with your elbow it hits one of the pillars in the room destroying as it falls on multiple demons. You raise both of your hands in the air lightning forming between them, forming a large trident.

Y/n: Lightning Dragon: Heavenward halberd!

You threw it forward killing the demons in its path. You jumped back to gain their distance and bumped into Yui who did the same.

Y/n: I got a question?

Yui slashed her sword killing a demon in front of her.

Yui: What is it?

You threw a lightning bolt killing multiple demons in the process.

Y/n: Don't demons usually have a leader they follow around?

Yui then freezes.

Yui: They do.

Y/n: Soooooo. How powerful is the leader.

Just then a loud roar could be heard, the demons all stopped and slowly backed away from the two of you. You heard giant footsteps getting louder and louder with each step. Just then from the darkness a huge fist comes racing towards you, you raise your arms in front of you to block it but was still thrown backwards from the force of it. You crashed into a wall and out of the building rolling on the ground until you stop.

Y/n: Ow. My back.

You groaned as you pushed yourself up.

???: Tell us where she is and we'll make it quick!

In front of you was a giant demon.

Y/n: Holy.

???: Tell me where Mio Naruse is!

Y/n: I don't know what your talking about.

He then jumped up into the air bringing his giant fist down on you breaking the floor beneath you he continues to pound his fist on the ground where you were standing.

Y/n: Keep going I don't think you got him yet.

He turns around to see you leaning right next to the wall you came crashing through with your arms crossed.

???: How did you-

He stands up glaring at you.

Goliath: How dare you make a fool out of the mighty GOLIATH!!

He leaps forward attempting to swipe you with his right arm. You quickly ran towards him and slid right underneath him as he smashes against the wall you were leaning on. You stood up and wiped the dust off your shoulder.

Y/n: Goliath huh. Well then I guess I'll be your David.

He comes charging out of the building raising his right arm as he was going for a punch you quickly jumped over him and land behind him as his fist hits the ground his fist stuck in the ground. You then jumped on his back and ran towards his neck with a small leap you grabbed his horns and brought it down as his face hits the ground. You picked his head up by his horns and kneed him under his chin and slammed his head back into the ground. You put your foot on his head in a cocky manner

Y/n: Ready to give up?

With his free hand Goliath grabbed hold of you.

Goliath: NEVER!

He pulled his right arm up freeing it. He stands up bringing you towards his mouth.

Goliath: Now I'll devour you whole.

You started punching his arm attempting to free yourself but to no luck. He slowly brings you to your mouth.

Y/n: EAT THIS!

Raising your arms up in the air the sky begins to make a thundering sound you bring your arms down. Suddenly a giant blue lightning strike from the sky struck him electrocuting him

You held up for a couple more seconds until an explosion happens between the both of you making him fly a couple feet away, while you go flying into the air and fall straight to the ground, you hit the ground and started bouncing off it until you finally come to a stop.

Y/n: That was bad ass. But that hurt so much.

You slowly stood just to see Goliath grab a chunk of the ground, you quickly noticed a lower mouth on his stomach like the stray devil you encountered before. He puts the chunk of ground in his lower stomach you noticed fire inside the mouth. Before you know it the mouth opens as a giant fireball comes flying at you, quickly dodging to the left the fireball hits the ground behind you making a small hole where it stuck.

Y/n: That's quite an appetite you got there.

Goliath: I must find Mio Naruse her blood is a very special sacrifice. I must have every drop to be king of the underworld!

He gets on all fours and leaps at you attempting to swipe at you again. You cocked your right arm back lightning emitting from it waiting for him to get closer.

Y/n: Lightning Dragon-

Within arms reach you hit him in the center of his face.

Y/n: Iron Fist!

He flys backwards and hits the wall. You instantly clutched your right arm in pain.

Y/n: Damnit that hurt!

You look over and saw Goliath slowly stand up clearly tired.

Goliath: I'll be king not him!

He smashes his fist in the ground grabbing a fist full of the ground, he puts it in his lower mouth ready to fire another projectile at you. You kneeled on the ground putting a your hand on the ground lightning surrounding your body.

Y/n: Lightning Dragon-

He fires the projectile at you

Y/n: Sword Horn!

You fly forward meeting the fireball head on you, you hit the projectile destroying it as you head straight towards Goliath's lower stomach which was still open. Head first you entered his mouth feeling the heat as you charged through him exiting through his back leaving a hole right in the back of his lower mouth. You come crashing to the ground rolling around until you dug your hands into the ground stopping yourself. You look back at Goliath as he was silent his body begun to slowly evaporates in the air leaving nothing behind. You stand up holding your right arm as you walk back into the building limping. Unknown to you someone was watching the whole fight as he smokes a cigar

He blows the smoke out of his mouth, he smirks.

???: Not bad kid.

Making your way back in the warehouse you see Yui finishing off the last demons. She quickly turns around to see you limping.

Yui: Y/N!

She quickly ran over to you as you fall into your her arms.

Yui: Are you okay?!

You slowly close your eyes smiling.

Y/n:(Weakly) David made that look so easy.

Yui couldn't help but smile seeing as you were alright. You let sleep take over you.

Yui: You did good son.

Yui put your arm around her shoulder and held you as she carries you back home. When she takes a step outside she notices the man that was watching you stand right where Goliath evaporated.

Yui: Jin is that you!

The man gave Yui a small smile and walked over towards the both of you.

Jin: I seen the whole thing he's got some talent. But he needs to work on his approach flying head first into its stomach that's pretty ballsy.

Jin then threw something towards Yui who caught it with her free hand. Looking at it she sees a broken piece of a nail.

Yui: What's this?

Jin: A little trophy for him a piece of that demons nail.

Yui inspected it turning it around.

Jin: He's quite the fighter. Summoning lightning from the sky I haven't seen anything like it. But he's not the only dragon slayer out there.

Yui brought her attention to you.

Jin: But he's different from the rest. I have a feeling lightning isn't the only thing he can do.

Jin then made his way over to you and picked you up and hoisted you on his shoulders.

Jin: He's got a long way to go. I only hope we have time.

Yui looked ar Jin confused.

Yui: What do you mean.

Jin: Not here let's go somewhere more private.

Yui nodded as they headed towards your home.

(Timeskip)

Jin was setting on a chair smoking a cigarette until Yui came and snatched it out of his mouth.

Yui: no smoking in my house.

Jin: Okay okay.

Yui set tea on the table and brought one for Jin.

Jin: Thanks.

Yui sat down on a couch where you were laying down on passed out.

Yui: Now tell me what's going on.

Jin set his tea on the floor clearing his throat.

Jin: I have a lot to say so listen carefully. The demons were here for a girl named Mio Naruse.

Yui: Mio Naruse?

Jin: The former Demon Lord Wilbert Daughter.

Yui: Daughter?!

Yui stared at Jin shocked.