Kazuto coated his whole body in haki so he doesn't get any surprises and even his observation haki was up. At first, he wanted to test just how strong nomu was, so he crossed his arms and took the first punch from nomu.
Kazuto was sent flying into the fountain at the centre of the area. Shigaraki commented "In the end, you are just an immature student. One punch was all it took. You are not worth being a mini-boss."
Kazuto got up from the debris without a scratch. He said "Never underestimate a mini-boss. Do you know how many people quit after facing Margrit the fell omen."
Nomu again blindly charged at Kazuto, but this time, he just tilted his body and easily dodged the punch. The punch changed the air pressure and the wind from it ruffling his hair.
Kazuto immediately threw a punch at Nomu. The punch connected with its jaw and Shigaraki said "Didn't you see your friend try to punch it and fail. He has shock absorption." but what he saw next shocked him. The Nomu staggered back from the punch.
Shigaraki was shocked and then confused "What is happening? Why is he taking damage?"
Shigaraki turned to Eraser head, who was still on the ground unconscious. Shigaraki went to full panic mode and started scratching his neck. His neck already had marks from the constant scratching and new ones appeared.
He mumbled "Did he stagger? Does that mean his shock absorption is not working? Can this kid also cancel quirks? That can't be possible, no one has multiple quirk. His quirk is clearly Super-strength. Does that mean master lied? No, he would never lie. No."
The Nomu again threw a punch at Kazuto and he effortlessly dodged it. Kazuto again countered with a punch to its gut. The Nomu just staggered and continued its attacks. The barrage of punches continued and not a single one hit Kazuto. He was dodging all of the attacks and countering with a punch or kick.
Midoriya, Asui and Mineta were watching the fight, if you call staring at two blurred figures. Their eyes couldn't follow Nomu and Kazuto's movements. Mineta said "Kazuto, you can do it."
Midoriya started mumbling something and then said "We have to help Kazuto. We can't just sit here while he is holding of that big villain."
"Good that my haki punches are affecting him, but he immediately heals with his regeneration. I can't use any holds or judo throws. It would come down to who can last longer and the brain dead nomu would obviously win." Kazuto said in his head and then heard Midoriya scream "Smash".
Kazuto turned to see Midoriya, who went for Shigaraki when he was distracted. While this looked like a smart move, it wasn't . "WHAT IS THIS IDIOT DOING?" Kazuto screamed in his head. If Shigaraki is in danger, the Nomu would defend him instead of fighting Kazuto.
Nomu threw another punch at Kazuto and Kazuto was distracted by Midoriya. Kazuto couldn't react in time to dodge and had to block the attack.
Kazuto was sent flying again and the Nomu charged at Midoriya to defend Shigaraki. Before Midoriya could attack, Nomu caught Midoriya's arm and snapped it. Midoriya screamed in pain and tried to escape from Nomu's grasp.
Shigaraki clamed down and said "Right, it doesn't matter if your punches affect him. Nomu can regenerate instantly. He can even grow back limbs in seconds."
Kazuto said "Don't get so excited, it is time for second phase of the mini-boss. Also, did you say regenerate? So, I can use my sword without any worry." walking towards them. His left hand pushed the Tauba (guard) of his katana with his thumb. He then drew the katana with his right hand and held it in front of him.
Shigaraki looked at Kazuto and said "Nomu, leave these students to me and kill that idiot."
Nomu again charged at Kazuto, this time trying to grab him. Kazuto jumped to his right and immediately slashed Nomu's feet. With his haki and the sharp blade, it was a clean cut.
Nomu lost balance and fell to the ground, its feet still on the ground away from nomu. It wasn't even long before the Nomu grew new ones.
Shigaraki said "See, anything you do is pointless. I still had fun seeing you try 'mini-boss'."
The Nomu got up and tried to punch, but Kazuto dodged the punch and sliced off Nomu's wrist. Another one took its place and the Nomu continued.
Asui reacted in time and wrapped her tongue around Midoriya. Shigaraki took notice and charged at Midoriya, but Asui was faster. She dived into the water with Midoriya and swam away. With the villains stuck together in the centre of the lake, they were safe. She surfaced when she was far from both the villains in the lake and Shigaraki.
Shigaraki stomped the ground angrily and said "Nothing is going as planned. All Might's not here, Kurogiri is knocked out, Nomu is taking too long to finish one student and I couldn't even kill one student."
Shigaraki then turned to the fight, a fight he never expected to see. The indestructible Nomu he brought to defeat the symbol of peace, All Might, was getting his arms and legs chopped off by a student who joined UA three days ago. There were wrist and feet scattered all over the centre area, and blood splattering everywhere. Kazuto's clothes were drenched in blood, his white shirt completely red.
Kazuto said in his head "Good, my attacks are working. His regeneration, although still fast, has slowed down significantly than before. Even his attacks are getting slower. Even if you engineer him to be the ultimate villain, quirks are physical abilities and no one can engineer unlimited stamina."
Shigaraki observed the fight from far and said "Nomu retreat back and use a wide area attack."
"Shit, this is going to be a problem. Can't let him go far." Kazuto said in his head and immediately chopped off his legs. The Nomu didn't stop. He grew his legs immediately and tried to move back. Kazuto didn't let him do that.
Shigaraki said "Just punch him when he comes for your feet. This feels like a pokemon battle." and the Nomu followed his order. Since Kazuto was close, he couldn't dodge in time and had to block the attack. He was again sent back flying, but this time he recovered quickly and tried to close the gap between them. Kazuto was late though, the Nomu already had enough gap between them and punched towards him, the punch creating an air pressure, that prevented him from getting closer. He wasn't taking any damage and was also walking towards the Nomu, but it was slow.
Shigaraki then said "Nomu, throw things at him, with the wind pressure, they would travel at crazy speeds."
Nomu obeyed and uprooted the half destroyed fountain. The Nomu threw it at Kazuto with all its strength. Kazuto said "Shit, that will definitely deal a lot of damage. I have to do something. Quickly, tell me something. Wait, what would Shanks do? What would Zoro do?...'Slash'."
Kazuto immediately stood in his place, eyes closed and focused on the flying debris with his haki. His grip around his katana tightened and the world around him slowed down. He used all his strength, concentration and the experience from years of hardwork, into a downward slash.
Shigaraki felt something was wrong and shouted "Nomu, dodge." but it was too late. A huge vertical slash of air, caused from the air pressure from Kazuto's katana, travelled towards Nomu. The debris in the middle wasn't even an obstacle and split in half. The slash kept travelling and left a deep vertical slash on the Nomu.
Blood sprayed out of the wound and Nomu fell to the ground. This was the perfect time for Kazuto to close the gap between them, but Kazuto didn't.
Kazuto stood in his spot breathing heavily as he gripped his sword. The fatigue built up from maintaining haki all over his body, constantly using observation haki and dodging Nomu's attacks while countering. He didn't have enough haki to maintain both observation and armament haki, so he turned off armament haki.
Kazuto said in his head "No problem, just have to survive until All Might gets here. What's taking them so long? Iida already went to get help and didn't I knock out the guy jamming the signals? Didn't Kaminari contact someone outside? The alarm system is probably fried, so can't rely on that. Where is that hulking blonde idiot when you need him?"
Kazuto prepared himself to dodge, when a trail of ice made its way to Shigaraki and Nomu. Before they could react, their limbs were frozen.
Kazuto turned to see Shoto walk towards the centre area. Shoto said "Kazuto, you are using way too much force. You look more like a villain than a hero. I will handle it from here."
Kazuto wanted to scream, but life wasn't done playing with him. He heard a voice scream "I will kill you bastard".
Bakugo came flying into the centre area and landed to his left while Shoto was to his right. Both of them were far from Kazuto. Kazuto turned to look at Bakugo and saw Kirishima run towards Bakugo, Momo following him.
Momo said as she ran "Kazuto, I brought help. You said we all must fight togeth....." but stopped when she got close to the centre area.
When Kirishima and Momo arrived at the centre area, they looked at the scene with complete shock. Kazuto drenched in blood and countless limbs scattered all over.
Kirishima asked while trembling "What happened here?"
Momo was too scared to speak and even puked out her lunch.
Kazuto screamed "WHY IS IT THAT SUDDENLY EVERYONE IN THE CLASS DECIDED TO TURN INTO THE DUMBEST PEOPLE ON THE PLANET? CAN'T YOU SEE THAT I HAVE BEEN TRYING TO KEEP THAT IDIOT HERE SO THAT HE DOESN'T GO AFTER YOU?"
Bakugo, being the idiot he was, shouted "Shut up scarface. If you can handle him, I can easily handle him."
Kazuto wanted to punch him in the face, but then said "You know what, you are right. You should probably handle the big guy."
While they were debating, Kurogiri was busy dealing with ice. He used his quirk and the ice around him started crumbling. He was already getting frostbite and it was getting worse. With the little feeling he had left in his arms, he started to decay the ice to escape.
Shigaraki said to Nomu "Nomu, escape from the ice and kill those students."
The Nomu started trying to move and Shoto said "I wouldn't do that if I were you. Your limbs would get separated from your body."
That was exactly what happened. The Nomu tore its torse away from its frozen limbs and fell to the ground. The Nomu wiggled around, blood gushing out from the wounds.
Kirishima, Momo, Bakugo and Shoto couldn't believe what they were seeing. The Nomu then grew a new pair of limbs and charged towards Shoto. Kazuto couldn't move that much, his muscles refused to move. That's why he thought of just dodging Nomu's attacks so that he can stall till Allight gets there, but they ruined everything.
Kazuto shouted "Run" since he wouldn't get there in time, but Shoto's arrogant ass wouldn't move. He let out a wave of ice at Nomu, who punched it off easily. The Nomu arrived before Shoto and punched him in the gut, sending him flying into a nearby wall.
The Nomu didn't stop and charged at Bakugo and group. It completely ignored Kazuto. Kazuto again shouted "Run", this time running behind Nomu, but Kirishima and Bakugo didn't listen. Momo was the only sensible one there and she ran.
Kirishima hardened his skin and Bakugo had his explosive sweat ready in his gauntlets. When the Nomu got close, he let out his most powerful explosion straight at Nomu.
Bakugo said "Take that Brain freak."
Kirishima asked "Did you kill him?"
Bakugo said "Were you struggling so long to deal with him? Guess you are not that strong after al..."
Bakugo didn't even get to finish when a punch landed on his face through the smoke from the explosion. Bakugo was sent flying into another wall nearby.
Kirishima shouted "Bakugo" and turned to the Nomu. The Nomu didn't waste time and threw a punch at Kirishima. The punch connected with Kirishima's hardened arms and didn't even slow down. He was also sent flying into a wall.
The Nomu then turned to Momo, who was running. Kazuto ran after the Nomu, trying to get to it before it got to her. The Nomu was faster and closer to Momo than Kazuto. The Nomu got to Momo before him and was about to punch her in the face.
Kazuto said in his head "Shit....shit ...shit...I won't make it in time. Shoto, Bakugo and Kirishima are durable, but Momo definitely can't survive a punch from Nomu. Come on. If you can't even save the girl you like, you are useless. A normal slash can't stop him, it will only leave a cut."
Kazuto then concentrated all his strength and haki into his katana and sent a vertical slash aimed at Nomu's fist. The wind slash, which also had haki, travelled through the air and sliced Nomu's wrists off his hand.
Since Nomu's regeneration had slowed down, it gave enough time for Kazuto to get to Momo. The Nomu punched again at Momo, but Kazuto pushed her away and took the blow. His haki was drained and he was completely tired.
Kazuto took the punch and went flying into a wall. Shigaraki shouted "Leave the girl. Kill him."
The Nomu charged at Kazuto, who couldn't even move. The Nomu slammed into him, punching him repeatedly and throwing him through another wall.
Momo looked at the scene with complete horror "Do something, but what? That thing is immune to everything and it also has regeneration. Think Momo, he is in this situation for saving me."
That's when she heard a voice she recognised "Everything is fine, because I am here."
Momo turned to the entrance where a hulking figure with blonde hair in a yellow suit was standing. She burst into tears when she saw him "All Might...".
All Might didn't speak much and immediately charged at the Nomu who was still beating up Kazuto. He punched the Nomu in the face, but it didn't budge. All Might was shocked, but didn't let it affect his judgement. He immediately saw asmall window and picked up Kazuto.
When he was far enough, he looked at Kazuto and said "Villains, you will pay for what you have done." his tone reflecting the anger he felt.
Seeing All Might, Midoriya asked Asui to take them to the centre area. Although Shigaraki freed himself from the ice, he couldn't use his limbs from the frostbite.
All Might handed Kazuto to Momo, who was still crying and said "Young Yaoyorozu, take young Kazuto and get him to safety."
Momo couldn't carry him alone, so Midoriya came to help her. Momo said "Midoriya, your arm."
Midoriya said "Kazuto is in a serious condition than me."
Asui and Mineta were helping Aizawa and they headed towards the entrance of USJ. Momo kept crying as she looked at Kazuto's bloodied body.
Midoriya said "Don't worry Yaoyorozu. He will recover from this and be back to his cheerful self."
Momo just nodded and hoped for the same.
Back to All Might, he was standing in front of Nomu and said "You scared students and almost killed one. I will never forgive you for this."
Shigaraki said "Scared? Don't joke All Might. Look around you. That kid you saved chopped off so many limbs from Nomu that you could make five new Nomu from them."
All Might then charged at Nomu and it did the same. The battle went exactly as in the anime, except All Might wasn't injured and Nomu was weakened by Kazuto. The battle ended quickly and All Might then turned to Shigaraki, who was already immobilized.
All Might walked towards him to capture him when black liquid started coming out of Shigaraki's mouth and for Kurogiri, it came out from above the metal plates, but from where, no one knows.
All Might rushed towards them to stop them from escaping, but he was too late. Shigaraki and Kurogiri disappeared. All Might screamed in rage "NO!!"
In the attack on USJ, 2 teachers, 5 students were injured while the main villains escaped.