At the Rias Gremory Occult research club we see Rias and the rest of her group just relaxing when both Y/n and Raynare came to their club. At first they were surprised that he brought Raynare here especially Issei but Y/n explains what happened and after he told them his story they all sat around and think about the situation.

Rias: I see. This is very bad indeed. If that Fallen Angel try to become God who knows what he will do.

Y/n: That's the reason I come here for help. There is another house hold I can call up but they are busy and besides you guys are pretty good when it comes to combat so you guys are my only group to save Asia.

Issei: Look man I want to save Asia I really do, but I'm not working along with Raynare here.

Y/n: She was betrayed by her own kind.

Issei: Well she shouldn't have killed me! Or hurt me? Or...whatever! She shouldn't have betrayed me after that date!

Y/n: Look what happened in the past is in the past. Now we have a common enemy and that is the one going to use Asia to make himself God and his fallen angels will be killed just like he tried on Raynare.

Raynare: Look I'm sorry about before but right now we have no time for this. We need to stop him before it's too late. I know you all may not trust me but now we have to work together.

There was silence in the room for a short while and then Rias sat up and tell the two.

Rias: We'll help you just tell us what you like us to do?

Y/n: Raynare told me their hide out is at an abandoned church outside of town so here's the plan. Rias ans Akeno will stay outside and make sure no other Fallen Angel would escape while me, Raynare, Issei, Kiba and Koneko will enter inside and take them on. If things go south you and Akeno will come in and back us up.

Rias: (smirk) Nice plan. Alright we can fallow with that plan.

Akeno: (smile) This is going to be fun for sure.

Kiba: (smile) Help you Y/n no matter what.

Koneko: Time to kick some asses.

Y/n turns to Issei who looks at him and to Raynare and then to Y/n and then sighs and tells him.

Issei: Fine I'll help.

Y/n: (smirk) Awesome. Now then, let's go and trash their little party.

(Later)

It was the middle of the night as we see Y/n, Raynare, Issei, Kiba and Koneko making thier way through the woods and then arriving at the front entrance of the church. Once at the encounter Y/n walk up to the door, kneel down and try to unlock the door.

Y/n: (whisper) Give me a second to get this door op-

Then Koneko kicks the door open which surprised Y/n as the door swings open.

Koneko: Knock knock.

Y/n: (smirk) Nice one Koneko.

She nodes while they head inside and see nothing but broken windows around them as well as dusty chairs and just dust everywhere.

Issei: Seems like no body is home. You sure this is the right location?

Raynare: They are underground. That's where the ritual will be taking place.

Y/n: Why is all rituals have to be taking underground. Well if that's the case how can we get down there?

Raynare points at the door at the left side of the church so they approach the door and open it. They were faced by staircases that go down with a trail of candles guiding them as they slowly make their way down the steps.

Kiba: Seems like they have been here for a long while.

Raynare: This has always been our hide out after The one found us. He wanted a home to all Fallen Angels who was kicked out from Heaven.

Koneko: So why forming a large Fallen angel group?

Issei: Probably us them as pawns so he can get what he wants?

Y/n: Huh this may surprised me to say this but your probably right Issei. After all he did throw Raynare away and even try to kill her at the park.

Issei: Say speaking of that what were you and Asia doing after you defeated Freed?

Y/n: (smirk) Why? You jealous?

Issei: Shut up!

Kiba: Ssshhh quit. Do you guys hear that?

They do hear something. They hear a group of people chanting as they made it at the end of the staircase and make their way through the halls. Soon they reached two large doors which they slowly open and peak through to see a massive crowd of cloak figures along with The One looking down on them with Asia being strapped onto a cross and beside him where Mittelt, Kalawarner and Dohnaseek as The One listen to the chanting and then the chanting stopped as The One tells his followers.

The One: Today is a great day for us Fallen Angels! No more that we fall to our failures and to our shame any longer! No more that we call ourselves Fallen Angels to the angels above us because as soon I have become God, I will use my powers to sent all of us to heaven! This is the day that we will achieve our goal!

The cloak figures cheered as The One turned to Asia and walk up to her as he reach out his hand as he gose on to say.

The One: She will be our savour and her sacrifice will never be forgotten!

Then Asia felt like something was pulling out of her and she start to scream in pain while red bolts of electricity was coming out of her body as The One continues to suck her sacred gear out of her when suddenly the doors were kicked open by Y/n as he and the rest rush inside as Y/n calls out.

Y/n: (smirk) That's some lie you told right now.

The cloak figures all turn to see them. The One was shocked that they have found their hide out while Mittelt and the rest were shocked that Raynare is alive.

Mittelt: (shocked) The hell? Raynare, I thought you were killed?!

Raynare: He lied to you just like he lied to all of us! He never wanted us to make us angels again, he just want the power for himself while we were pawns to him!

Kalawarner: (shocked) What?! You can't be serious.

Raynare: It's true! He nearly try to kill me!

They were shocked by this while the One sees this and then summons a spear and throws it at them but lands a blow to Dohnaseek as he yells in pain before he blows up, sending Kalawarner and Mittelt flying and crashing onto thr floor.

Soon he managed to pull Asia's Sacred gear out of her as she puts her heaf down as The One looks at the two rings he has as he start to laugh and puts them on.

The One: Finally. Now I will take revenge on the gods and rule heaven with a iron fist! As for you all, your all done.

He then summon multiple spears and fire them all at his followers which they were all killed within seconds and blow up. Y/n and the rest were shocked by this as Mittelt and Kalawarner rush over to Raynare while The One floats down and lands onto the floor while he looks up at them and tells them.

The One: Do you really think you can stand a chance against me now?

Y/n: (smirk) You really wanna know the answer?

The One: (smirk) No.

He then fired a blast which they all dodged and they all attack at him. They try to land some blows at him but he was too strong and when ever they do land a hit at him, he just heals his wounds up like they were nothing. He let out a laugh whioe Mittelt, Kalawarner and Raynare attack him which he blocks their attacks.

Mittelt: Your going to pay for lying to us!

The One: (smirk) Oh please you three were the most fools then ever. So despite to go back to Heaven after your sins!

He quickly took them down as they were sent flying. He turns to the rest and noticed Y/n not among them so he turn and see Y/n freeing Asia and pick her up.

Y/n: Asia.

The One: Leave my prize be!

He was about to charge at him but then Kiba blocks his strike while Kiba tells him.

Kiba: Get out of here Y/n! We'll hold him off!

Y/n nodes and carry Asia out of the room and soon they made it to the church as he set Asia down which she woke up.

Y/n: Hang on there Asia. Your going be alright.

Asia: Thank you Y/n. I'm so glad that.....I can get to see you for the last time.

Y/n: Don't say that Asia. I'll save you.

Asia: (smile) I've always loved you Y/n. Your so kind, brave and a person I've never met before. I was always alone until I met you. I'm happy.....to meet a person I love like you. I don't care what you are or what others say about you. In my eyes......your a....... good person.

Y/n grabs hold of her hand as Asia stare at him with a smile and then shuts her eyes and took her last breath. Y/n sees that she is dead as he lower his head down while he shake his head.

The One: What a cute sight. I never know he could fall in love with a devil.

Then The One was behind him as Y/n stood up but didn't turn to him as he gose on to say.

The One: (smirk) I can understand why she was called a witch. She should have know that devils like you should never be healed or be friends with. No matter, now she is gone now. Which is great.

Y/n: She was a nicest person I've ever met.

The One: Huh?

Y/n: She never care about anything about anyone. She just wanted to help and yet the world treat her like shit. She deserves better after all the kindness she did to those she helped. She didn't deserve to be called a witch, be kicked out or even be used as a sacrifice. You have made your biggest mistake in your whole life.

He then turn to The One and then there was a burst of darkness which The One and Rias from outside felt which was impossible. Then Issei and the rest came out to see Y/n as he glare at The One and then says to him.

Y/n: Now.....time for you to see what happens to those who harm my friends, especially Asia!

He snap his fingers and suddenly there was a burst of darkness that surrounded Y/n which shocks everyone to sense his power and soon the dark cloaks burst away, revealing Y/n's dark armor as he glare The One through his helmet.

The One: (shocked) No! That can't be possible! Don't tell me your the Dark slayer!

Issei: (thought) The Dark slayer?! Wait that's the story he told me about?! I didn't know he was the Dark slayer dude!

Kiba: (shocked) I don't believe it!

Koneko: (shocked) The Dark slayer. He's real.

Raynare: (shocked) I didn't know he is the Dark slayer!

Mittelt: (shocked) Same.

Kalawarner: (shocked) Agree.

The One: No matter! I'll crush you even I have to rip-off your armor off!

He throws holy spears at him but they bounce off like they were just sticks being thrown at him.

The One: (shocked) What?!

Y/n: Listen here asshole. If your going to harm or kill anyone who is pure and innocent. How's about you face with someone that isn't hesitate to end your fucking life within seconds!

The One: Oh shi-

Then within seconds Y/n quickly grabs The One by the face and then slammed him hard onto the floor, creating a large shook that made Issei and the rest to stumble while Y/n grabs The One and the two burst through the ceiling as Y/n takes him into the air and once at the air he strike powerful blows at him, costing him to spit out blood as Y/n continues to land blow after blow at him.

The One try to land a strike at him but Y/n catches his fist and then rips his arm off as The One screams in pain as Y/n pulls out Asia Sacred gear out of his fingers and then tossed his arm away and then appear in front of him and land a elbow strike at us stomach which he spits out ever more blood and then he lands a powerful blow that sent him flying down and crashing into the church.

Rias and Akeno head inside to see the is going on but they were surprised to see Y/n is his armor as he slowly lands onto the ground and then walk towards The One while Rias and Akeno were shocked as everyone else.

Rias: (shocked) I don't believe it.

Akeno: (shocked) Agree. It seems he is this legendary warrior from the books. The Dark slayer.

Then Y/n grabs The One by the neck and lift him up in the air. The One gasp for air while Y/n took off another ring off of him and sees now he had Asia Sacred gear back as he look at The One.

The One: You.....can.....never.....bring....her....back....to.....life.

Y/n:......Just fuck off.

He then slammed his hands through The One, killing him immediately as he legs go and his body fell onto the floor. He wipe off the blood off of his hand and then changed back to normal as he breath in a sigh and walks over to Asia and set her sacred gear on top of her.

Y/n: Here you go Asia. Sorry we could have save you sooner. Shit, wish there was a way to bring you back to life.

Rias: Well there is.

He turn to see Rias and the rest as she approach him and tell him.

Rias: Just like I did to Issei I can bring her life and have her be apart of my house hold.

Y/n: You can do that?

Rias: Of course. Are you familiar with chess? Each chess piece is ranked by my members of the house hold. I'm the king, Akeno is my queen, Koneko is my Rook, Kiba is my knight and Issei is my pawn.

Issei: (mutter) Unfortunately.

Y/n: So what leaves Asia at the chess pieces then?

Rias: She will be a Bishop. But once she is brought back to life she will be a devil. Do you want me to do this?

He turn to Asia and knows she deserves for a second chance of life so he turn back to Rias and tell her.

Y/n: Do it please.

She node and walk up to her and reach out her hand towards her. There was a red glow as everything turn red before turn into darkness.

(Next day)

Y/n: Aaaaaaannnnnndddddd this is where you be staying!

He opens the door to show Asia her new room at Y/n's mansion as she step inside and looks around as Y/n straches the back of his head while he tells her.

Y/n: (smile) Sorry if the room is not what you think of-

Asia: (smile) I love it! Thank you for letting me stay here Y/n!

She then hug him which he smiled and hug her back. Once that he leaves her to unpack and walks over to Lucifer as she ask him.

Lucifer: So she's now a devil?

Y/n: Yeah. Thanks to Rias she's now brought back to life and now apart of her house hold.

Lucifer: (smirk) While you being a agent to them.

Y/n: (smirk) I might as well be a agent to a lot of house holds.

Lucifer: (giggle) Still glad to have her here.

Y/n: Wish Raynare, Mittelt and Kalawarner can stay here with us. But I guess they need to find their own place to stay.

Lucifer: Agree. Say want to help me to make lunch for everyone?

Y/n: (smirk) Sure thing.

The two head off with Y/n turning back to Asia's room as he smiles and then continues on. Soon we see everyone at the dinner table eating the delicious foods while Asia gets along with everyone as she smiles and laughs with them. He smiled at her seeing her getting along well as they enjoy their lunch like a happy family.

To be continued...............................