Y/n POV

*Bang*

Y/n=Hey don't start the party without me!

Everyone=Y/n!!

Y/n=Looks like I came at the right time..

I then shoot the monsters around them.

*Bang*Bang*Bang*Bang*Bang*

After that i went toward them.

Y/n=So what happen?

Origami=Nia is now turning into an inversted spirit.

Y/n=Nia?

I then looked at the spirit that was floating in the air.

Y/n=Oh, She's been a spirit all this time

Y/n=Well, i not notice that before.

Y/n=Anyway, What makes her goes inversted?

Origami=Well, We don't know!

I then looked toward Shido.

Y/n=What have you done this time Haremist?

Shido=I- I don't do anything!!

Shido=Anyway, Everyone..!

Shido=I don't know what is happening… but I know I can't leave it like this!

Y/n=Well, Here comes the brave Shido. The Girls conqueror!

Shido=Y/n! Now isn't the time to joke around!

Y/n=Oh, What did you just say? I not heard your voice because it's too small

Kotori=Stopped you both!

Then suddenly more pages start coming out of Beelzebub and creating even more countless number of monsters.

I then summon Yamato and perform judgemend cut end to those monster.

And in the blink of an eye all the monsters were destroyed.

Y/n=It's too easy for me!

Shido=…Will Nia turn back to normal if I kissed her…?

Y/n=Well, I don't know about that. But since you don't have any other ways....

Shido=You're right!

Shido=I will help Nia. Everyone… please lend me your power!"\

Everyone except me=Yeah!

Then suddenly a voice is heard from somewhere.

Isaac=I'm sorry to say that won't be possible

After that, a girl in a silver uniform appeared from the sky.

She came down to the ground on the opposite side of Shidou with Nia in between in an appearance that believe herself is the
strongest being in the world without any doubts.

Ellen=Because i'm here!

Y/n=And what's the matter if you're here!
I shouted to her.

Ellen then looked toward me.

Ellen=Shut up if you not want to die!

Y/n=Die? Haha you almost make stomach hurt haha!

Ellen= I don't plan to talk with you.

She grip the hilt of her equipment in her back and draw it out. It is Ellen's personal weapon that made its
blade of a magic power laser blade, Caledvwlch

monsters around Nia then start attacking Ellen at once.

Ellen knit her brows a little and use her Territory to defeat all those monsters.

Ellen=Looks like demon king's power is a little troublesome. Let's finish it fast.

Ellen then use her Territory to spring herself into Nia while raising her Caledvwlch.

Before Ellen could get close to Nia, i teleported in front of her and kicked her with Gilgamesh.

Y/n=i won't let you..

Ellen=So you intend to interrupt me. It's fine if that's the case then I won't show any mer-

Suddenly with the blink of an eye I rushed towards Ellen and kicked her again.

Y/n=Stop talking and started fighting fool

Then suddenly she appear right in front of me and try to slash me with her sword but i simply blocked her attack with royal guard.

Ellen=What!?

Y/n=Surprised?

I then attacked her with blinding fast punches. Ellen is being pushed by me a little by
little.

Y/n=What is the matter? Can't keep up?

Ellen=Yo-

Before she finished her word I attack her with a powerful uppercut.

Ellen then slammed through a few building.

Y/n=Done.

Kotori=Kaguya, Yuzuru, Miku,
Yoshino, Natsumi, Origami try to get rid of the dark monster around Nia and clear the way for Shido! We can't waste this chance!

Shido=Let's get it done quick!

Then suddenly yoshino legs froze down to the ground with her own power, Natsumi transformed into a mascot character like something repelled Hanniel's power back to her.

Shido=Don't tell me…!

Shido=Future describing…!

monsters then start closing to Shido and others.

Before those monster attack them, i summon Yamato and attack those monster with judgemend cut and then i perform judgemend cut end to monster around Nia.

Y/n=Shido quickly go to Nia!

Shido=Hai!

Shido then run toward Nia and i follow him from behind.

Shido=Nia!? Can you hear me!? I'm going to help you now!

Nia=Shi… do…

???=That's not good if you do that.

Something then fly to front of Shido from the sky in
high speed and exploding light.

Y/n=What the..

Shido=Ni—a? Nia!?

Y/n=Shido what happen!

I then looked toward him. And i see Nia is get stabbed by a sword.

A clot of blood then came out of Nia's mouth.

Y/n=Nia!

Shido=You! What have you done!

Shido grip the hilt of Sandalphon tight and swing it to the girl with all his might. However, before Sandalphon could reach the girl's body, she
use her Territory around her to stop it.

Shido=What!?

Then the Territory expanded out of sudden and blown Shidou's body away.

I then cacth him.

Y/n=damn Shido don't let your anger control you!

Shido=S-Sorry, Y/n. Thanks.

Y/n=*sigh*whatever

Artemisa then put her strength into the hand that is gripping her laser blade and take the blade out of Nia's body.

Nia's body bounced when Artemesia take out her blade and blood start coming out from that wound like a springwater.

Shido=Nia!

Artemesia then raise up her hand and hold it above Nia's chest.

Artemesia mumbled something in her mouth and the Territory around her begin to change.

The same moment, Nia's body also start emitting a dark
light.

The next moment, an object that looked like a crystal made by condensing the night into it appeared from Nia's chest. At the same moment, Nia's Astral
Dress then dissolved into a dark haze.

Shido=Sephira!?

Y/n=Sephira? What is Sephira?

Suddenly i senses someone walk closer toward our location.

All spirits also turned their face into the same direction. With everyone looking, that man walk calmly toward Artemesia. The man with ash-blond hair in a black suit.

Y/n=You!

Shido=Isaac westcott..!

Isaac=It has been a while since we met directly like this, Itsuka Shidou and Y/n Sparda. I'm glad
to see you both in good health.

Westcott said that while stopping his feet at front of Nia. He look at the black crystal that is floating above her and make a smile full of insanity.

Isaac=Splendid. So this is... Inverse Spirit Crystal Qlipha.

Isaac=Thanks for you work, Artemesia. Looks like it was a right decision to have you hide yourself just in case.

Y/n=Hey what are you doing

Isaac=What, you asked? Haha, is it your place to ask that?

Westcott grab that crystal with his hand and push it toward his chest.

A pitch-black flash then start spreading around the place from Crystal with a sparking sound.

As if the area around them has turned into a night in a
blink of an eye. Few seconds later that 'night' then gathered and absorbed into Westcott. There is no crystal to be found anywhere.

What is there is only Westcott with his suit burned in the chest covering with spirit power. As if he is a spirit.

Isaac=Haha, Hahahahahahahaha! Hahahahahahahahahahahahahaha!

Y/n=Nothing funny here you Lunatic

Kotori=That can't be… did he just take Sephira into him…

Shido=No way that could be..

Isaac=The power of… spirit…? That's the case.

Westcott then raise up his hand in the air, and chant

Isaac=Beelzebub!

Isaac=Oh…? To my surprise, even though this is the first time I've had my hands on a demon king, I know the power and ability of it quite clearly. I guess this is how?

Isaac=I see… ability to manifest the being written in the book. A power that could
bend over the reason and logic of the world, worthy of the name of demon king. Don't you think it's terrific?

Y/n=Nah, not really

Isaac=huh?

Y/n=cih...why everyone i meet is a crazy dudes that obsessed to be a demon.

Y/n=hey westcott, i could destroy that book if i want thought

Isaac=Hahahahahhaaa but that is only in your imagination

Y/n=You challenge me? Alright then i will show you What a demon is.

Isaac=then show me

Y/n=Well, prepare to die

Isaac=what the-

I then suddenly appear in front him.

I pull my Rebellion and and try to slash him but he blocked my attack with his book but that book instantly destroyed.

Isaac=What!? How that possible!?

I then summon Ivory and pointed it toward westcott.

Y/n=Any Last Word?

Isaac=What are you!

Y/n=Demon...

I then channeled my demonic energy to Ivory and then I shot Westcott with my seal abilities.

*Bang*

After i shoot him suddenly a portal appear behind him and pull him in.

Y/n=You're going to visit the underworld

Isaac=What!

Then the portal closed.

Ellen=Westcott Sama!

Artemisa=Westcott Sama!!

I then turn back to my human form.

Kotori=Y/n What are you doing to Westcott

Y/n=Nothing i just send him to the underworld Forever...

[Small timeskip]

I was now watching Shido kissing Nia to make her wake.

Y/n=Why i see this right now....

Shido=Nia! Nia! Wake up, Nia!
Nia… san!

Other spirits also call for her. And not long after, Nia eyelids started moving. She then say a word with her hoarsed voice

Nia=I can… hear it… already… You don't… need to… shout…

Shido=Nia!

Y/n=I should leave now..

Shido=Y/n wait!

Y/n=What

Shido=Thanks for your help today

Y/n=Well, No problem...

Y/n=Now i must leave... My stomach is already starving so bye, Haremis and And congratulations on having a new girlfriend

I then leave.

[At y/n Apartment]

Rinne=so y/n what are you doing at the spacequake

Y/n=Help Shido defeading inversted spirit and sealed Isaac westcott

Rinne=Wait you sealed Isaac westcott? How?

Y/n=Well, i just shoot him with my sealing abilities. Not pretty hard thought

Rinne=I thought DEM would be destroyed because of you.

Y/n=That is good thing right? No more spirit killing and no more DEM and you are free from them now

Rinne=You're right...

Rinne=Well i gues we don't have any problem again now

Y/n=Nah, i still have one more problem

Rinne=and what is it?

Y/n=let's talk about that later

Rinne=okay