Bankai, Minazuki.

15

Everyone who was inside that room earlier with the exception of MeiMei and Yaga, ran to rescue the students but a veil was casted. 

Gojo tried to go inside the veil but he was denied.

"Hey.. why the hell can't you go inside?" Utahime asked while inserting her arm inside the veil.

"Ah I see, they're smart. This veil is an anti-Gojo Satoru veil, you guys go first." He motioned his pointer finger on the veil.

Gakuganji and Utahime went inside the veil while the four soul reapers were silent and standing beside Gojo.

"Hey why are you four just standing there??" Gojo asked.

"Umm well- some Soul Reapers can create veils like you sorcerers but they can't get pass it.." Rukia said frowning.

"WHAT?! why didn't you tell me this earlier??" He looked at Unohana who just smiled.

"It's okay we'll try to break the veil." Byakuya assured.

"Stay a little bit away from me..." Byakuya said as he released his Zanpakuto.

"Scatter, Senbon-" Byakuya was about to chant his shikai when suddenly a massive amount of pressure was released.

Gojo was coughing and kneeling, the two second year soul reapers were slightly paralyzed.

"GOJO!-" Unohana went to Gojo's side and started to treat him.

The people inside the veil couldn't feel the pressure, thanks for the veil protecting them. If there was no veil they could've died because of the pressure. Once Unohana was done treating Gojo the two of them immediately stand up.

'That Aizen Fucker.' Gojo cursed mentally.

"SHOW YOURSELF AIZEN!" Unohana shouted, her hair no longer braided.

"Welcome, to Jujutsu Society Kuchiki Byakuya, Kuchiki Rukia and Hitsugaya Toshiro."

while in the clinic:

The pink haired child and lilac haired girl widened their eyes at the familiar pressure.

"AIZEN!" they both shouted.

They looked at Shoko who was having a hard time breathing. Isane went to her side and treat her.

"Hana-san.." the pink haired kid worried.

"Everyone release your zanpakuto! Gojo standby there and wait for the curtain to open up!" Unohana commanded which everyone followed.

"Scatter, Senbonzakura!"

"Dance, Sode no Shirayuki!"

"Reign over the frosted heavens, Hyorinmaru!"

The three released their commands at the same time leaving Unohana alone who has not released hers yet. 

'This is my first time fighting together with Unohana! I better not mess this up!' Hitsugaya and Rukia thought.

The time they went to Aizen who was floating above the air, far away from the veil.

The veil was destroyed.

Gojo Satoru was now in the sky standing, scanning the area which was covered with veil earlier.

"Let's start there." He said

"WHAT'S THE COMMOTION UP THERE??!" Utahime shouted seeing the other four fighting an unknown person.

"We'll explain later." Gojo was now beside Gakuganji and Utahime.

"TCH! I told you they were no good!" The old man spat.