Minako: PERSONA!!!

She summons Metatron and uses Divine Judgement. It was super effected as she's able to figure out that Shadow Y/n's weakness is Bless/Holy. He screamed in pain as Ahikiko charges up a powerful punch.

Minako: he's weak the Bless everyone use them!!

Nanashi uses his device to summon Shiva and uses Akasha Arts. This severely damaged Shadow Y/n with the smirk damaged him more with the pierce.

Nanashi: how about that faker!?

Shadow Y/n: GRRRRRAAAAAAA!!

He climbs on the buildings, uses Devil's Spikes and shards of demonic energy rain down as everyone was hit causing mini explosions.

Shadow Y/n: IT HURTS!!

He screams as he uses Beam of God to attack. Beams strike down as Y/n blocks taking half of the damage but was low on his life force.

Y/n: I'm not.....GOING TO LOSE!!!

Y/n: this will be fun!!

He rushes towards his shadow and slices the tails and 3 of his claws.

Y/n: Strike from Messiah!!

Messiah appears with Izanami and Nyx arrived as they used Megidolaon causing a huge explosion. Y/n went up to the air and red/black aura surrounds Tensa Zangetsu.

Y/n:*mind* Come on, come on!!

Shadow Y/n turns around and ready his claw as both Y/n's charged each other.

Shadow Y/n: The strike of the cursed one!!

Y/n: GETSUGA TENSHOU STRIKE!!!

Shadow Y/n and Y/n: HAAAAAAAAAAA!!

Both of them strike each other as Y/n's weapon strikes the head while the claw strikes his chest damaging it badly. All of Y/n's weapons were now broken as both screamed in pain

Shadow Y/n and Y/n: GHAAAAAAAAAAA!!!

Both pulled out as blood came out of their body and fell from the sky. They crashed landed to the ground as everyone ran towards them.

[There should be a GIF or video here. Update the app now to see it.]

Rias: Y/n!!

The dust moved up in the air as everyone saw both Y/n's were bleeding badly.

Asia: Y/n!!

Ann, Yukiko, Yukari every healer were trying to heal them but it wasn't working.

Ryuji: it's not working!?

Shadow Y/n: our attacks damaged us greatly.

Y/n: we're not going to make it even if you tried your hardest.

Asia used her Twilight Healing but it wasn't working.

Shadow Y/n: so this is the end of the road of us?

Y/n: yeah it seems so my shadow...

Akechi: Y/n, you idiot!! Don't you leave me!!

Sachi: we went through everything together!!

Yuuki: please!!!!

Y/n: I'm sorry it seems that I'll be guided by a god more stronger than those false gods....hehehehe it's so....cool...it's alright...

Futaba: Y/n!! You're my key item!! I don't want to lose you!!! I lost my family!! Please don't leave us!!

Y/n: Forgive me...Futaba...

Eugeo: Y/n....I died so you can live back then...

Y/n: now it's my turn to have you....live...*coughs blood*

Shadow Y/n: I need...to....sleep...light...

Y/n: yes a eternal rest until the next life...

Both of their life force were gone. Everyone was silent and Rias began to cry.

(Timeskip)(1 month Later)

On a Hill Elizabeth, Margaret, Lavenza, Igor, Philimon were in front of Y/n's tombstone with his broken weapons on the ground.

Igor: forgive me, Y/n I've failed you.

Philimon: I've failed you to achieve the power of gods.

Elizabeth: I should've been there helping you...

Margaret: It seems that we couldn't reach your full potential. Now the world must battle YHVH and Yaldabaoth so the world can secure a better tomorrow.

Lavenza: I'm sorry....I'm sorry...forgive me my love...

Then the screen turned to white as a unknown figure watches from his screen.

????: no, this is not how I put it...

GAME OVER, TRY AGAIN?

CONTINUE OR RETURN TO TITLE SCREEN?
(This is not canon)