Aizawa Shota, hero name: Eraser Head, looked tired as always. The deep dark circles under his eyes left no doubt that he barely knew what resting was.
Even so, he led Class 1-A to the new task.
The buses stopped in front of the immense structure known as the Unforeseen Simulation Joint — USJ. The building had the shape of a huge dome, and inside it there were different zones designed to simulate catastrophes: fires, floods, landslides, storms, and even destroyed urban scenarios.
The first impression was that of a giant disaster theme park.
Rescue training.
That was the lesson of the day.
The hero Thirteen, a specialist in support missions, was put in charge of guiding the students. With enthusiasm, she began explaining each sector of USJ and the importance of practice: saving civilians was just as essential as defeating villains.
Aizawa stayed in the background, but he still watched each student individually. He knew the weak points of each one and was ready to step in if something went wrong.
Except the "something wrong" came far too soon.
A black whirlwind began to form in the center of USJ's main plaza as soon as Thirteen finished her speech. From that distorted fog, dozens of villains began to come out.
Armed men, criminals with strange appearances… all villains.
At the front of everyone, a man with hands covering his arms and especially his face, Shigaraki Tomura.
They introduced themselves as the League of Villains.
Aizawa reacted in the same instant.
"Thirteen, protect the students. I'll hold them off."
He jumped forward, his eyes fixed on the villains as his Quirk, Erasure, went into action.
Villains charging in with active powers had their abilities erased in an instant, leaving them vulnerable.
Aizawa moved with precision, his capture scarves spinning like extensions of his own body. In a few seconds, two, three enemies were immobilized.
His movements were fast and efficient, worthy of a highly capable Pro Hero.
But it was an uneven fight. More and more villains kept coming out of the fog.
Aizawa kept his focus, erasing the Quirks of some, knocking others down with direct strikes, but with each second the pressure on him increased.
Unlike other heroes, his power required a constant line of sight and the more enemies came into the field, the harder it became to control everything at the same time.
Even so, Aizawa stayed on his feet. Alone against dozens.
Because that was what a hero did.
While the students were scattered to the different areas of USJ by the fog of the villain Kurogiri, Aizawa launched himself at the leader, Shigaraki.
Aizawa managed to hit Shigaraki, but he grabbed Aizawa's elbow and began to disintegrate it with his Quirk.
Aizawa reacted fast, striking the villain in the face and knocking him back, before turning to defeat two more enemies who tried to surround him.
But then a wall of muscle rose up in front of him after stepping out of Kurogiri's portal.
The Nomu charged with a muffled roar, the stitched, grotesque body moving with brutal speed and strength.
Aizawa erased its Quirk instinctively… but nothing happened.
"What—?"
Before he could react, the Nomu's fist came down with absurd force, and the impact of the blow broke his bones.
Shigaraki laughed in an almost childlike tone.
"This is the Nomu. He was made to defeat All Might."
An enemy designed specifically to surpass the Symbol of Peace.
Aizawa tried to resist, even with his body already injured. He used his scarves, he tried to erase the powers of other villains around to relieve the pressure, but it was useless.
The Nomu did not back off. Each blow crushed him further into the floor.
Until finally Aizawa fell.
Blood ran down his face and his vision began to blur. Even so, his mind did not stop. He knew he could not simply stop there.
The students… they were still in the line of fire.
And it was at that moment, between one blink and the next, that a holographic screen appeared in front of Aizawa, perfectly visible even with his face pressed against the floor.
It was the "Dimensional Chat Group" system.
– – –
[It has been detected that member Aizawa Shota is in a dangerous situation.]
[Do you want to create an Emergency Mission?]
– – –
He did not know exactly how that worked or what kind of danger there could be in inviting one of the members to his world… but in that instant, it hardly mattered.
This was the only card left to protect his students.
And that was the most important thing.
The screen confirmed the creation of the mission.
– – –
[Emergency Mission issued.]
[Member Ayano Keiji has accepted your mission.]
– – –
The one who seemed least "trustworthy" among the members was the one who accepted.
As the Nomu raised its arm for the finishing blow, Aizawa saw out of the corner of his eye a figure materializing in the space.
A boy with light, tousled orange hair, wearing a traditional black Shinigami shihakushō, with a sword at his waist.
He looked young. Older than his Class 1-A students, but not enough to look like an adult. He was like a teenager, like U.A.'s Big Three.
Aizawa had expected a "Shinigami" to have a more mature appearance, but he had no time to reflect on that.
"Yo, Aizawa-san. Looks like you really needed help."
The newcomer's voice echoed calmly.
Shigaraki froze for an instant, his trembling fingers stopping. The Nomu hesitated, and Aizawa, exhausted, could only let out a heavy sigh.
The situation had changed.
A "Soul Reaper" had arrived.
And he did not waste time.
With a single Shunpo, Keiji appeared beside Aizawa and cut off the Nomu's arm that was holding him down with a swing of his zanpakutō.
The thud of the Nomu's arm hitting the ground sounded dull, and before the creature could even regenerate or react, Keiji pointed his hand and cast a spell.
"Hadō #31, Shakkahō."
The red sphere of condensed energy exploded at close range, hurling the Nomu away with devastating force.
Gripping Aizawa by the shoulder, Keiji pulled him with another Shunpo and took him to the group of students who were still gathered nearby. With surprising care, Keiji set the hero down and knelt right after.
He set the zanpakutō to the side and extended his hands as a green light began to glow, soft and steady. It was Kaidō, the healing technique for which the Fourth Division was known and sought after.
Aizawa's wounds began closing quickly enough for him to breathe without so much effort.
The students surrounded them, all shocked by the scene.
"Who is he?"
Asui Tsuyu murmured, eyes wide.
"Is this guy a pro hero? What's his Quirk?!"
Mineta exclaimed.
Midoriya stood there, eyes wide as he tried to process each different thing he had seen.
High-speed movement, red sphere, healing…
But Keiji completely ignored the students, keeping his focus on Aizawa.
"Aizawa-san, tell me. Should I eliminate these villains? That creature doesn't look very human. Its reiatsu is weak, but the body is pretty tough, since it withstood a direct Kidō from me."
Aizawa coughed, blood still staining his mouth, but managed to answer between heavy breaths.
"Priority… is the students' safety. Avoid killing… if possible."
It was at that moment that Kurogiri manifested beside Shigaraki, his dark fog spreading across the field.
"Tomura… one of the students escaped. The situation is no longer favorable. We should withdraw."
Shigaraki growled, scratching his own neck in frustration, but did not argue. The plan had already derailed ever since they did not find All Might the instant they arrived.
Now, a new "hero" had appeared out of nowhere to interfere.
Keiji, for his part, finished the Kaidō until Aizawa was in minimal condition to move on his own. Then, with a quick motion of his free hand, he raised a translucent barrier in front of the students — Bakudō #73, Tozanshō — blocking any immediate threat.
Only then could he focus on fighting.
Then, with another Shunpo, he vanished from in front of the students.
When he reappeared, he was right at the center of the field, facing the crowd of villains and the Nomu, which had already regenerated its lost arm.
"Yare yare~"
He twirled the zanpakutō in his hand with a loose motion, the blade reflecting the artificial light coming from USJ's dome.
"I just got here and you already want to run? That's not fun at all."
At the very same instant, the atmosphere changed. Keiji's reiatsu spread without restraint, a dense, suffocating weight that settled over the entire area.
The villains began to tremble. Some fell to their knees as they felt their legs give out.
A Shinigami's reiatsu was something they had never experienced. For those who only knew the "intimidation" caused by the presence of strong heroes, this was like having their very bodies crushed.
Even the Nomu, which had been created to withstand the Symbol of Peace, faltered. Its muscles shook, and for a second the abomination seemed more like an animal trying to fight instinct than a purpose-built soldier.
This was Keiji's way of making sure no one tried anything stupid while he had his fun against the Nomu.
Shigaraki's eyes went wide as his fingers compulsively scratched his arm and his lips trembled. Hate and fear mixed on his covered face.
"What… is that thing?! Wh-what Quirk is that?!"
He could barely raise his head to face Keiji.
Keiji smiled from the corner of his mouth, a calm, almost amused expression, watching the Nomu get up once more and charge at him.
"Let's have a little fun~"
The Nomu's muffled roar echoed through the space. It ran, the ground shaking with each heavy step, and the students in the back fell into absolute silence as they watched.
The creature's body was a monstrosity with exposed muscles stitched together, its blackened skin hardened like stone, and an aura of blind rage. The monster stretched out its hand, trying to crush Keiji.
'Was this what gave Aizawa-san trouble?'
{It's like a hollow, but it has even less awareness.}
Sora's voice echoed calmly in his mind.
Keiji nodded, agreeing. From the weak reiatsu the Nomu gave off, it was doubtful whether "it" even had a complete soul.
In the next instant, he moved. The zanpakutō flashed in a quick arc, and Keiji vanished with a Shunpo.
The sound of the swing came right after, when Keiji appeared behind the Nomu, cutting with precision. The strike opened a deep furrow across the creature's back.
The blood barely ran before the muscles began to close up in absurd regeneration.
"Regeneration, huh?"
Keiji commented under his breath, watching the tissues knit back together.
In Hueco Mundo, Adjuchas-class Hollows had some level of regeneration, but not all were that efficient. This monster was beyond normal, as if it had been stitched together never to die.
Shigaraki laughed with his rasping laugh, even as he was forced to keep his forehead to the ground by Keiji's reiatsu.
"He can't be beaten with brute force! This Nomu was made to crush even All Might!"
Keiji blinked slowly.
'Who the hell calls themselves All Might?'
Of course, he would not ask something like that. All Might seemed to be someone famous, and showing he did not know him could be awkward.
Raising his free hand, he murmured softly.
"Hadō #63, Raikōhō."
A golden flash exploded as a beam of condensed energy struck the Nomu head-on. The electrical discharge coursed through the creature's body, frying nerves and muscles for an instant before hurling it into the arena's rubble.
The impact was strong enough to break part of USJ's reinforced concrete structure.
The villains screamed. Some tried to run, but Keiji's reiatsu swelled even more, filling the air as if the oxygen had vanished.
"What… what damn hero is he?!"
One of them yelled exactly what everyone else was asking themselves, whether the villains or the U.A students themselves.
Keiji paid them no mind. Shunpo took him back to the battered Nomu. The abomination was still getting up, but its movements were uncoordinated.
With clean cuts, Keiji hit the tendons in its legs, severing them before the regeneration could catch up. The Nomu crashed down heavily, its arms dragging along the ground as it tried to rise.
The tip of the zanpakutō rested against the monster's chest.
"Hadō #33, Sōkatsui."
The blue flash exploded, engulfing the creature in spiritual flames. The sound echoed through the entire dome, the pressure of the energy tearing up the concrete around it.
When the smoke cleared, the Nomu was still alive. Deep burns covered its body, but the muscles were already twisting, trying to regenerate again.
"This is going to be a lot of work."
{It looks like it dispersed part of the Kidō's shock. Must be another Quirk.}
'Didn't Aizawa-san say each person can only have one Quirk?'
{That thing does not look like a person.}
'When you put it that way~'
Shigaraki, who was watching everything, screamed with a raspy voice, nervous and excited at the same time. His fingers scratched his arm compulsively, almost tearing chunks of his own skin.
"Kill him, Nomu! Finish him! Kill! Kill! Kill! Kill!"
The Nomu roared, a guttural sound that reverberated like a beast trapped in hate, and it charged again.
Keiji closed his eyes for an instant, just feeling the creature's unstable reiatsu. He tried again to use the Observation Haki that Hancock had told about, but no different sensation came, making him sigh. When he opened them again, he dodged the punch in microseconds and slid along the flank with a Shunpo.
The blade flashed in a clean arc and the Nomu's entire shoulder was ripped off.
But as before, the flesh writhed, stitching itself together at a grotesque speed.
Keiji let out a short laugh.
"Yare yare… looks like I am going to have to play a bit more seriously."
His reiatsu spiked all of a sudden, an even more suffocating weight that made the villains forget the act of breathing.
Shigaraki shrank even more, his head forced against the floor as his hands shook with what could only be described as "absolute dread."
"Close your eyes for a moment, kids."
Keiji's voice echoed calmly, directed at Aizawa's students who were watching him with wide eyes.
He still remembered Aizawa's recommendation to avoid deaths, but dragging this out only put everyone at risk.
Even if he was being selective, keeping them exposed to his reiatsu could cause some unnecessary harm to the kids.
And they were supposed to be the future heroes who would protect this world, so Keiji could not let anything happen to them — which was also part of the mission's brief.
In the next instant, Keiji vanished. The wind from the Shunpo swept dust and shards, and when he appeared again, he was already above the Nomu, bringing his zanpakutō down in an arc.
The cuts came in sequence, dozens in seconds. Tendons, joints, organs — everything was sliced before it could fully regenerate.
Every time the body regenerated, another cut broke it down again.
He was moving so fast that the students' eyes could no longer keep up. To them, the Nomu was simply coming apart again and again with no chance to react.
"Absurd physical endurance, continuous regeneration, and a body that does not get tired…"
Keiji spoke under his breath, the tip of the sword pointed at the creature still piecing itself back together.
"Enough of that."
He raised his free hand and began to chant a full incantation. The reiatsu vibrated in the air, heavy enough to make USJ's metal structure groan.
The students stepped back on instinct, their hearts racing under that pressure. Aizawa's eyes went wide when he felt the true level of a "Shinigami."
"Hadō #73, Sōren Sōkatsui!"
The blue energy fired in two layers, devastating the Nomu completely. Flesh, bone, and blood were vaporized. Not even ashes remained after the spell.
The impact destroyed half of USJ's structure, cracking walls and shattering the floor.
Even the villains stayed frozen, even without Keiji's reiatsu pressing them down, fear stamped across their faces.
Keiji twirled the zanpakutō and rested it on his shoulder, looking at the empty space where the Nomu had existed seconds before.
"Maybe I overdid it a little?"
Would this be another case of Coughing Baby vs Hydrogen Bomb?
The students, still protected by the Kidō barrier from the remnants of the attack, could barely breathe. Midoriya clenched his fist with wide eyes, unable to process everything he had seen.
A monster created to defeat All Might... was taken down just like that.
"Well then, shall we deal with you now?"
Keiji shifted his gaze to the villains. At the very instant his reiatsu disappeared, Kurogiri tried to activate his Quirk, Warp Gate, to escape with Shigaraki.
He was not even interested in the other villains.
But Keiji was already in front of him, the Shunpo putting him face to face with the living fog. He crouched down slowly with half-lidded eyes, and let his reiatsu press straight down on Kurogiri, forcing him to lose the focus needed to use his Quirk.
"Your ability has to do with space, isn't it? I should be careful~"
Shigaraki gnashed his teeth, his whole body trembling. His voice came out broken, almost childlike, but full of hate as he tried to crawl up.
"You… you will pay for this!"
But before he could get up, USJ's doors blew apart with violent force.
A tall man, heavily built, emerged through the dust with a wide smile on his face.
"All Might!"
The atmosphere changed again.
The Symbol of Peace had arrived.