~from Reader's POV 2nd person~
After exiting the room Yamori had tortured you in, you made your way, barefoot, down the halls, led by some instinct that you couldn't quite place. On the way there, you came across multiple groups of Aogiri members, mostly in 3's or 4's, which you quickly destroyed. The old you would have been disgusted and horrified with the efficient death you bestowed upon them, but it was all clear to you now. To be weak was to wait and hope luck was on your side; to be strong meant you took action and made luck your own personal bitch.
So you went on, making your way up floor by floor in a methodical manner, driven by instinct alone and running on a chillingly calm and scary sense of calculation.

~from Kaneki's POV 2nd person~
Still feeling sick, you followed Touka. More and more often, you came across small teams of Aogiri that had been slaughtered very recently.
"Follow me," Touka said, moving swiftly towards a door marked STAIRS by a sign that was tilted and on the verge of falling off.
"But don't we have to find (y/n) first?" you asked, pausing just beyond the door.
Touka hesitated before turning to face you. "Kaneki..."
"What if she's further down this hallway? We haven't checked all the rooms yet," you said, brows furrowed in confusion. "What aren't you telling me?"
Touka turned, letting the door to the stairwell slam shut. "Kaneki. That room. Do you remember it?"
You immediately knew which room she was talking about about. "Yeah." You shivered, still terrified by the inhumanity and cruelty of what you'd seen.
"What did you see in there?" she asked, avoiding eye contact.
"The man..." you began, stopping. No need to go into further detail when the image was seated into both of your memories.
"Do you remember the chair in the center of the room?" Touka asked, still not looking at you.
"The chair..." You tried to picture the room in your head. "I saw it, but after I saw him...it didn't seem as important."
Touka nodded before speaking. "There were...chains...attached to the chair," she said, finally looking at you.
"Were there?" you asked apprehensively, still not understanding whatever point Touka was trying to get across to you.
"Kaneki...I think your sister was being held in there."
You froze, shaking your head. "No...no, you can't be...you can't be right. That man..." Touka didn't say anything, just gave you time to process. "Well, if she was there," you choked out, struggling for every word, "then where is she now?"
Touka stared at you hard. "Kaneki. (Y/n) killed the man in there, and all of the dead Aogiri we've seen in this hallway can't be a coincidence."
You shook your head, eyes wide in horror and disbelief. "No...no, (y/n) would never do something like that."
"You saw that room, Kaneki." Touka looked away. "You saw all of the tools stuck in him. That room is where your sister was tortured. To survive something like that...it changes you." When you didn't respond, she grabbed your hand and dragged you into the stairwell. "Look. She's cutting a path floor-by-floor to the roof. If we take the stairs, we should be able to beat her there and intercept her."
You stumbled up after her, silent. Is it true, (y/n)?
***
You followed Touka up the stairs and almost ran into her when she stopped in the doorway to the roof.
"Ayato," she said, taking here steps towards him and placing herself between the two of you.
"Touka." Ayato watched her for a second before grinning with a malicious gleam in his eyes. "You're still hanging around with the losing team, huh?" He nodded towards you, smirking and laughing meanly. "He's the weakest twig at your cafe that I've seen so far. Even the girl was stronger than him."
"Girl?" you asked, ignoring Touka's glare as you took a few steps towards Ayato, no longer blocked by Touka. "Did she have long black hair and (e/c) eyes?"
Ayato smirked. "Maybe. Maybe not. I'm not that great with the little details. But now that you mention it," he said, pausing and tilting his head as if in deep thought. He smirked. "She looked a lot like you."
"What did you do to her?" you asked, grabbing him by the shoulders.
Almost before you made contact, you were propelled back into the brick wall, hitting it hard and feeling it in every bone of your body. A few bricks were knocked loose from the old structure.
"Didn't your parents tell you to look, don't touch?" He asked, shooting you a look of pure disgust.
"They're dead," you said, brushing little bits of rubble from your shoulders and shaking the dust out of your hair.
Ayato sneered at you. "Really? Well go cry yourself a f**king river. Nobody cares if your family is dead. It's not like you're the only f**king orphan in the entire world."
"Ayato," Touka said in warning, her eyes burning. "You've crossed the line. Don't go taking out your pain on others."
He laughed bitterly, his eyes mad. "You think I have one flying f**k about the weaklings who raised us? Hell no. They were weak, and the only option for the weak is to die by the hands of the strong. Watch and learn, Sister." He turned his rage back to you, and as you stood up, you brought out your kagune, trying to look strong, but Ayato saw right through you. "You're pissing yourself right now, aren't you?" he mocked, hitting you over and over again, ruthless and relentless in his attacks. "No," you finally got out, ducking his kagune and standing up to punch him in the face.
"Why does a weakling like you think you can take on someone as strong as me?"
"Because," you said, bleeding from a dozens wounds, "I've got someone to fight for, someone I need to protect."
A transient look of shock crossed Ayato's face before he hid it with his classic smirk. "If you're protecting someone, I'd love to see how much of a weakling they are to need your help."
As if summoned, the door to the roof slowly creaked open.