(I changed the bio a little because a few ideas came to my mind)

*3rd person POV*

After a few minutes of running Y/N arrives at the ORC, he open the door inmediatly to see Isa laying on the couch unconcious while Akeno was healing her.

Y/N:How is she?

Rias:Right now she is just unconcious, she should wake up in a few minutes.

Y/N:I see, Rias we need to save Asia.

Rias:I know but we can't go without a plan.

They hear someone speaking and notice is Isa talking in her sleep with a blush and a smile that screams pervert.

Isa:*sleep*W-wait Y/N we can't do that right now.

Everyone in the ORC had diferent reactions to her, Rias and Yuri sweatdrop, Akeno had a blushing face imagining some...questionable thouths, Koneko kept her stoic face but Y/N.

Y/N:

He didn't like what was going in her mind.

Isa:*Sleep*N-no not there, it's sensitive.

Y/N:

Isa:B-be a little more gen-

Before she could finish Y/N kicked the couch making her fall in the floor and wake up.

Isa:Hey! What's the big idea! I was dreaming very go-Y/N!!

Y/N:You know i would usually do something about that but right now we don't have the time.

Rias:Give me some time and i will call you when everything is ready.

Y/N:Yeah i will wait for your call but i don't think we have much time.

*Timeskip, next morning, Y/N POV*

I'm currently walking in town in more casual clothes since it's a weekend and i see a very familiar blonde girl.

Y/N:Asia?

Asia:Y/N?

Y/N:What happened?

Asia:W-well after what happend that day, they kinda let me go.

Y/N:I see, that's good then.

Y/N:*Thouths*She is not telling the truth.

Y/N:Are you hungry?

Asia:Just a little.

Y/N:Follow me then.

I take her to a restaurant and we both order burgers but it looks like Asia is seeing her burger weirdly.

Y/N:Are you ok?

Asia:Oh yeah, just how do you eat this?

Y/N:Oh, sure.

I showed her how to eat the burger and when she took a bite her eyes sparkled.

Asia:It's delicious!

Y/N:I'm glad to hear that.

After that we went walking through town, we even went to an arcade, she had some trouble with the games but i was able to teach her how to play them.

We were currently walking in the park until a fallen angel appeared in front of us.

???:Asia, where were you?

Asia:Lady Raynare!

Y/N:Asia! Stay behind me!

Raynare:You must be the human that Freed told us about.

She summons a light spear and aims it at me.

Raynare:Unfortunatly for you this is where you die.

She throws the spear at me, i was able to dodge it and transform as i summon Arsene to kick her but she was able to dodge.

Raynare:I see you are quite skilled, but what will you do if i do this!

She creates another light spear and throws it to Asia, i rush to protect her and use Arsene to block the spear but even with Arsene blocking the attack it hurts like hell.

Y/N:*Thouths*DAMN! EVEN BLOCKING WITH ARSENE IT DOES THIS MUCH DAMAGE!

I fall to the ground as Arsene dissapear along with the transformation and i begin to cough blood, Raynare aproaches me but Asia gets in front of me.

Asia:Wait! Please let him go and I'll go back!

Raynare:Very well, come here my dear Asia.

Asia walks to her and Raynare flies away with Asia.

My vision is getting blurry and i see a red light and a person but due i can't see who it is.

Y/N:*Thouths*Red, could it be?

After that i black out.

I wake up but I'm in the velvet room, i stand up and see both Igor and Lavenza.

Lavenza:Good you are awake, we were worried for a moment.

Igor:Indeed, in this moments your body is unconcious but you don't need to worry, someone is already aiding in your recovery.

Lavenza:I ask for your forgiveness, because i didn't thaught you how you change your personas you are now on this condition.

Y/N:Don't worry about, but could teach me now?

Lavenza:Of cource, watch closely.

*One persona change explanation later*

Y/N:I see it dosen't look complicated.

Lavenza:Indeed, although it seems we ran out of time, your body is waking up.

Y/N:Alright, thank you for teaching how to change personas.

I close my eyes and when i open them i notice that I'm in my room, not only that but i feel something soft in my hand and for some reason i give it a squeeze and i heard something i never would get to hear.

???:*Soft moan*

I instantly stand up and i see Rias naked in my bed.

Y/N:*Thouths*WTF, WHAT IS SHE DOING HERE NAKED?!

???:*In echo*Because the plot demands it.

Y/N:*Thouth*PLOT?!WHAT ARE YOU TALKING ABOUT?! AND WHO ARE YOU?!

???:*In echo* Dosen't matter she is waking up.

I see Rias waking up and she looks at me.

Rias:Good morning Y/N, how are you?

Y/N:Oh, good morning Rias, wait! What are you doing in my room? And why are you naked?!

Rias:Well the healing i performed on you requires to have phisical contact and it's more effective without clothes and i don't like to sleep with clothes, besides it's not like im the only one naked here~.

Y/N:What do yo-

Then i realize i was naked all this time.

Y/N:

Y/N:R-rias, w-why am i n-naked?

Rias:Well like i said, the healing is more eficient if we are both naked.

Y/N:I s-see.

I quickly grab my pijamas and put them on.

Rias:You are cute when you get embarassed.

Y/N:A-anyway, what time is it?

Rias:Its seven in the morning.

Y/N:I see, do you want to eat breakfast then?

Rias:That would be lovely.

Y/N:Ok, put your clothes on while i prepare breakfast.

I head to the kitchen to prepare breakfast.

A few minutes later Rias came and sit in the table and i serve us both breakfast, she takes a bite and her eyes sparkled.

Rias:This curry is delicious, where did you learn to do this?

Y/N:Someone in my hometown thaught me how to make it since i spend some time with them because my mom was busy with her job.

Rias:I see, if you don't mind me asking, where are your parents right now?

Y/N:They are in my hometown due to their work, although they comes to visit some weekends.

Rias:Well then we should get going, we don't want to be late for school.

Y/N:Yeah.

We got prepare for school and walk there, after a few minutes we arrived at the entrance.

Rias:Meet me at the club after school so we can discuss the plan.

Y/N:Right.

*Timeskip brought to you by chibi Y/n watching Isa getting shot with a chalk*

Me and Isa arrived at the ORC and when we enter we see the rest of the club.

Rias:Alright everyone is here, now let's discuss the plan, Y/n, Yuri, Koneko and Isa will go through the front door while me and Akeno go to the forest where the rest of the fallen angels are, does everyone understand?

Everyone:Yeah!

*Timeskip 3rd person POV*

Currently Y/N, Koneko, Yuri and Isa are in the front door of the church.

Y/n:Ok how should we proceed.

Koneko:They already know we are here.

She walks to the front and kicks it destroying it.

Y/N transforms and they enter the church and see a familiar stray priest in front of them.

Freed:We meet again, you know it's my policy to not fight the same devils more than once since i always kill them but i guess i can make an exception.

He turns towards Y/N.

Freed:And you, Lady Raynare already told me about you and your weakness to light, so this should be easy!!!

He rushes towards them with a sword made of light but Yuri gets in front of him and clashes blades with him.

Freed:Well looks like I'll have to start with you!

Yuri:I disagree, Holy Eraser!

Suddenly Freed's sword got absorbed into Yuri's sword.

Freed:What?!

Yuri:Holy Eraser is a sword that absorbs holy light.

Freed takes out his gun and shoots it to Yuri but it was blocked by an ice wall.

Freed:What the hell?!

They turn to see Y/N with his new persona that made the ice wall.

Freed:Another one?! Lady Raynare didn't told me about this!

He shoots two bullets towards Y/n, he dodges one but the other strikes in his leg.

Y/n:Damn, still hurts*smirk* but not as much.

Freed:But ho-

He was interupted by a bleacher(i think that's how they are call) that Koneko threw at him.

Freed:Damn! This is too much, well it seems that i need to go, see you later devils, bye bye!

He throws something to the floor which causes a flash and he dissapears

Yuri:He escaped.

Y/n:We need to keep moving.

They enter a basement where they found a bunch of priests and Asia hanged in a cross with Raynare at her side.

Y/n:Asia!

She looks at him.

Asia:Y/N!

Raynare:It seems you were able to defeat Freed, not that it matters, you are late, the ritual is almost complete.

Y/N tries to run to Asia but is surrounded by the priests, that is until Yuri, Koneko and Isa begin fighting them.

Yuri:Keep going!

Isa:We'll handle this!

Koneko:Go now

Y/N:Right!

He runs towards Asia but even though most of them were fighting the other, some were in his way so he had to finish those fights as soon as posible.

When he is closer to Asia he sees a bright green light surrounding Asia and two rings come out of her body and Raynare holds them.

Raynare:Finally, twilight healing is mine, with this no one will defeat me.

Asia falls out of the cross but before she hits the floor Y/n catches her.

Y/N:Asia, Asia!

Asia:Y-Y/N?

Y/N:Yes it's me, I'm sorry, I was weak and i couldn't help you.

Asia:*weak*Y-you are wrong Y/n, you did h-help me, when you hang out with me that day, I f-felt happy, Y/n I'm happy that you are my friend.

Y/N:I'm happy you are my friend too Asia.

Asia closed her eyes with a smile and after a few seconds she stoped breathing.

Y/N:Asia... Asia?...Asia!

Isa aproaches Y/n and puts her hand on his shoulder.

Y/N:Isa please take care of Asia

Isa:Y-yeah

Y/N gives her Asia and summons Arsene.

Raynare:This again?

She summons a light spear and throws it to Y/n, when it was about to pierce him Arsene grabed the spear without even looking and destroyed it.

Raynare:What?!

But before she could say anything else Arsene grabed her and threw her out of the basement.

She stands up to fly away but feels increíble murderous intent which paralizes her in place, she looks back to see Y/N without Arsene standing a few meters away from her.

He starts to pull his mask off but can't take it off so he rips it off and blood starts to come from his face and Arsene appears as blue flames surround him.

The rest of the ORC arrived at the scene including Rias and Akeno who were dealing with the other fallen angels.

The blood starts to disapear and he opens his eyes and everyone is surprised to see his eyes changed to yellow.

In everyone's eyes they could only see Arsene behind Y/n but Raynare was terrified she saw something extremely powerful, something that could kill gods with a single attack.

Arsene uses a curse attack which surrounds her and explodes only leaving black feathers.

Arsene dissapears and his eyes return to their normal color.

He aproaches Asia's body that was laying in one of the bleachers, with Isa at her side taking care of her.

Y/n:I'm sorry Asia, i couldn't save you.

Rias:Y/n, maybe this is not the solution you would like but there is a way to bring her back.

Y/n:Turning her into a devil, right?

She just nodded hed head.

Y/N:I promised her i will save her, if this the only way please do it.

She nodded and took a bishop piece and started the ritual, and puts the piece inside her body, after a few moments Asia opens her eyes.

Asia:Y/N?

He hugs her as tears were running through his face.

Y/N:Yes it's me, Asia.

Tears started to fall out of her face while she returned the hug.

Asia:Thank you Y/n.