Eri and the Reaper entered the office of Overhaul and saw Overhaul and Sin Nemoto waiting for them. The Hero Killers arm themselves.

Overhaul: Welcome home little Eri.

Eri and the Reaper felt rage building up in them. The object of both their vengeance was standing right in front of them. They were ready to end this.

Grim Reaper: You're gonna pay Overhaul!

Overhaul: My concern is not with you Reaper. If I remembered correctly, I invited only Eri, not you.

Grim Reaper: Fucking deal with it!

Eri: This ends tonight!

Overhaul: Is that so? We'll see.

Without warning, Overhaul uses his Overhaul Quirk to merge with Nemoto. His body transformed into a monstrous form with sharp bird-like arms from his shoulder blades and his original arms becoming larger with sharp claws. The Reaper then shoots at the transformed Overhaul with his MP5 Submachine gun, but Overhaul picks up the Reaper and tosses him against a wall.

Overhaul: WELCOME HOME ERI!

Eri dodges Overhaul's attacks and proceeds to jump on his back and begins stabbing the back of Overhaul's neck with one of her swords. Overhaul then grabs Eri and slams her to the ground.

Overhaul: IS THAT THE BEST YOU CAN DO?!

The Reaper then shoots at Overhaul with his Desert Eagle.

Grim Reaper: HEY! I'M NOT DONE WITH YOU! 

Overhaul turns his attention to the Reaper as he rushes to him. The Reaper dodges an attack, but is met with a devastating punch which shatters his mask. Overhaul grabs the unmasked Aizen and looks at him.

Overhaul: So you're the Grim Reaper?! You seem familiar.

Aizen: That's cause I'm the son of the family you murdered! Byakuya Hanzo and Makoto Hanzo! I watched you kill them you bastard!

Overhaul: Then allow me to reunite you with them!

Overhaul begins to squeeze Aizen. Eri gets to her senses as she hears Aizen's screams of pain. 

Eri: (No! Not again! Not again!)

Not wanting to see Aizen die by Overhaul's hands, she decides to use her Rewind Quirk to reverse Overhaul's transformation. Overhaul and Nemoto are separated. 

Nemoto: Master?

Aizen then shoots Nemoto in the head with his Desert Eagle.

Aizen: Just the three of us now! Hope you've made your peace Overhaul!

Eri and Aizen charges at Overhaul. Despite the numbers, Overhaul still managed to keep up with the Hero Killers. Overhaul then kicks Eri to the ground after stealing one of her swords. Overhaul then turns to Aizen. 

Overhaul: You are a nuisance.

Aizen: I'll fucking show you a nuisance!

Aizen then charges with his combat knife and slashes at Overhaul, but he counters and plunges the sword into Aizen's chest. Eri gets up and sees Aizen with her sword in his chest.

Eri: NO!!!

Eri then pulls out the gun she took from earlier and aims it at Overhaul with tears streaming down her face as Overhaul turns to see Eri holding the gun.

Overhaul: Put the gun down Eri. We have much work to be done. We have great things to accomplish together.

Hearing that voice say that filled her with fear and distraught. She looked to see Aizen still moving. As Overhaul walks towards her, she's finds herself unable to pull the trigger. But in a last ditch effort, she aims at herself and pulls the trigger. The injector pumps the Quirk Destroying Drug into her, effectively destroying her Rewind Quirk. 

Overhaul: You fool! Do have any idea what you've done?!

Eri: I will not be your slave anymore! I won't allow myself to be a tool of your twisted plans! I'll die before I'm used for your ends!

Overhaul: Then you will die!

Eri then pulls out her sword and begins swinging at Overhaul, but he simply dodges each attack. Eri lands a slash at his face, but he retaliates by punching her in the gut and throwing her to the ground. Eri sees Aizen and slides the gun to him while Overhaul grabs her. Aizen then grabs the gun and aims it. He sees Overhaul ready to use his Overhaul Quirk to disassemble her.

Overhaul: We could've create a new world together. Restored it to it's natural order. But you have thrown it all away. Goodbye Eri.

Eri felt her life flashing before her eyes. She never thought it would end like this, but she felt at peace knowing that her suffering was going to end. But at the corner of her eye she saw Aizen holding the gun.

Aizen: O....O......Over.....OVERHAUL!!!!

Overhaul turned around as he pulled the trigger. The injector shot into Overhaul's neck and pumped the Quirk Destroying drug into his system, taking away his Overhaul Quirk.

Overhaul: N...no.....

Eri then gets free from Overhaul's grip and pulls out her customized knife. 

Eri: What's the matter? Feeling helpless?! That's exactly how you've made me feel all my life! Every nightmare you've put me through ends now! 

Eri felt her malefic aura overcome her as it paralyzed Overhaul in crippling fear. 

Overhaul: E...Eri? What......what are you?!

Eri: NOW DIE!

Eri lunges at Overhaul and begins stabbing Overhaul multiple times with the knife that bore her name. The rage and resentment she built up over the years was now in full display as she unleashed her anger onto the man who had brought her pain and misery. When she finished, Overhaul was dead. She felt his shadow finally vanishing. She then rushes to the wounded Aizen.

Eri: Aizen! Are you....

Aizen then pulls the sword out of his chest. Blood begins to seep out of his chest.

Eri: You're bleeding! We need to....

Before she could finish, she hears someone banging onto the door into Overhaul's office.

Aizen: G....go.....

Eri: No! I'm not leaving you behind! 

Aizen: Y...you....need to get Stain! I'd......I'd just slow you down! I'll.....buy you two time......

Eri: Aizen.....please.......

Aizen then pulls Eri over for a kiss. In that briefest moment, she felt love. When the kiss ended, tears began to stream down Eri's eyes.

Aizen: Now....now we're even.....hehe......now go......

Eri: They'll kill you.....

Aizen then pulls out his Desert Eagles. 

Aizen: I go out......on my own terms......Eri......now go!

As Eri leaves, she turns to the wounded Aizen as he gets up. 

Eri: Aizen......thank you......for everything......

Aizen nods as Eri walks through the exit of Overhaul's office. Once the doors close, Aizen pushes Overhaul's desk to barricade the door. Aizen checked the clips of his Desert Eagles.

Aizen: (One full Clip. One halfway through. Should buy some time.)

The entrance is soon broken open as Yakuza thugs swarm into the office. Aizen begins shooting but is soon overwhelmed. As everything fades, Aizen doesn't feel regret. Instead he feels peace. The man responsible for everything wrong in his life was dead. But more importantly, he was sacrificing himself for someone he cares deeply. Aizen felt at peace as the life faded from his eyes.