It was after Zen had ripped off the spine of the Fourth Sister, Uriel, that the war against the Holy Force could be considered ending. Gazing at the drowning landscape below, his mind calculated how much damage had been inflicted upon his force. The water level was receding, revealing carcasses with various abilities scattering around. There were no soldiers from the Holy Force because Uriel attacked on her own, trying to avenge the Second Sister, Gabriel, and the Third Sister, Raphael.
He had been able to extract some information about the nun that had brought him up for a few years, her name Michael, the First Sister. But ideological conflict had pushed her out of the Holy Force under her own sisters' hands and her name had been reduced to the Fallen, Lucifer in their scripture. Such blind faith in the Prophet, their leader, had landed them in front of him. Now with the majority of the military power gone, the Holy Force was a pig waiting to be butchered. The organizations aiding Zen's were "destroyed" due to Holy Force's attack so only his could get all the benefits.
But first, he needed to release Yoichi from the vault. That was his way of protecting this weakling of a brother of him. Despite having some conflict due to the younger brother's aspiration for justice and heroes, Zen could not stop protecting someone as entertaining to observe as such.
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What stood before Zen was a broken vault.
In his hand was the spine of the self-proclaimed Prophet that he had ended seconds ago after crushing the leftover defense force. He had spared the pitiful civilians being used as meat shields since it took too much time to kill them all. That action of benevolence could earn some brownie points in Yoichi's eyes.
He had tried to finish every business as fast as possible but it seemed some rats had been loitering around this place. With a single teleport jump, he returned to his throne inside the main base. All surviving generals beneath him were being treated but their pain was secondary.
"Find the rats that have infiltrated my vault. You have a day. Late, and death."
Leaving an absolute order, Zen teleported away to begin searching himself. Normally he would have some surveillance quirks put around the vault but the fight against the Holy Force had demanded additional caution. This was a mad rush to reclaim what was his.
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'Blond annoyance', that was what Zen thought as he was being punched in the face by this supposedly follower of Yoichi. It had been eternity in his perspective so seeing how the legacy of his brother being passed around was the only entertainment he could truly enjoy. Zen had not robbed his opponent of his ability, or in this era, his quirk. He wanted to see how far Yoichi's quirk could go. He was prideful.
Therefore, only using secondary quirks at best to lengthen the amount of time he could spend with the remnant of his brother, Zen was fine with being a simple final boss before world peace if what this man in front of him had been spouting was true. This world order was built by the ones dealing directly with quirks. Stealing, copying, destroying, creating, ... only powers that reigned above other powers could fuel stability.
His continue existence even after the turbulent period proved this. Firepower had caught up to quirk outputs and with no end in sight to the speed. More and more personnel were being deployed to hunt down weak quirk overlords in America and Africa. Zen could already foresee the future status quo from the modification in teaching materials for history and morals, the growing pillar of merchandises of heroes in economies, and the lack-luster control of low-level villainy. He himself had even struck a deal with those behind the shadows: leaving him alone, or else he would end their little play at world control. And the status quo was still being kept in place. Villains backed by the other side had formed together into an alliance to combat him on every grounds but even they knew that All For One was toying with them.
Therefore, even while being plummeted by this hero calling himself All Might, All For One was thinking about how much acting he might need to do to retreat from the fight before obliterating some safehouses of the World Government. He had tasted the quirks boosting All Might's performance, a hot, spicy concoction of sun-dried chili and fat. Familiar, and he wanted to add it to his collection.
He had his end of the deal to keep after all.
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All Might also noticed how his opponent had let him freely punching. Unease rose inside but All Might could only continue attacking. Then, All For One gripped his hands and stopped all momentum. The force holding All Might back was unlike any he had experienced before. Before he could pull back and deliver an elbow jab, All For One spoke up.
"I am thinking of a deal ... let say I retreat from Japan and you get to be free of fighting me in this vain quest to defeat me. How about it?"
"NO! Who do you think you are, All For One?! I will not-"
"Or I destroy Japan right now. You can stop me, sure. But can you stop me fast enough before I level Japan? Arrogant. You have always been dancing on top of my palm. Without the help from that experiment, the American government, and the Geniuses, what can you even do?"
"Kill you, right here and now."
"You seems to be mistaken about something. You are not strong enough."
All For One ripped one side of All Might's torso to shred. The pain from the previous fight time had slowed All Might's reaction but even then he doubted he could sense the attack at his prime. A feet pushed against the right shoulder socket and delivered a kick, tearing his right arm off cleanly. All Might could not maintain the jumping mid air and would have fallen down if not for being griped at the hair.
"I have been lenient. But stand proud, you are strong."
And All Might and his parts fell to the ground. All For One masked everything as his defeat, altered All Might's memory (which led to his discovery of the vestiges residing inside the quirk One For All), and disappeared to one of the many safe houses of World Government force in Argentina.
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"So this is the hidden weapons of you lots. Truly a magnificent showcase"
Laughing maniacally at his current state, All For One could only utter that. Half of his head had been damaged beyond repair because of the Singularity they had fired. His body was fighting against a rampaging quirked disease that thrived on devouring quirk factor and causing de-evolution to organism. Even more, the executive squad from the headquarter of World Government had teleported and had struck him directly with their quirks. Some of them were rare, powerful quirks he would salivate to add to his collection but then this time was just a warning.
"Did we get him?"
"No."
All For One blitzed to the farthest executive member in the back before the answer could reach the twenty other members. He implemented the kinesis quirks to prevent shockwaves and to de-limbs the members, perception-altercation quirks to control the information flow, and electromagnetic quirks to combat surveillance from that little satellite up there.
"The spicy one is not here, but you should be a good replacement."
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All For One was sitting in front of his most trusted ally, the scientist he had salvaged from the man's fall from grace. The man's hypothesis of a quirk doomsday was sitting in front of him but All For One's conditioning had prevented the scientist from seeing the dangers. In his mind, All For One was a savior to combat against the possibility of world-ending quirks.
"This amount of damage to your body will need extensive care. Is All Might really that strong?!"
"Of course, the hero is a fine example of what a hero should be. All powerful, all caring, all smiling. But let us return to matter at hand. How is the progress with your project, Doctor?"
"Wonderful, wonderful, wonderful! The first batch of replicate quirks is finishing in one more week. And from that data, I can fine-tune the process even more, Master!"
"I am thinking of making clones. Inferior clones solely for harvesting their quirks. Can this aid your research, my friend?"
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'How is it? My memory?'
A string of unfamiliar thought ran through All For One's brain.
'Who are you?', he asked.
'Who are you? Time to return.', the voice answered back.
'I am ...', "All For One" thought closely
"A material to be used to strengthen me.", said the All For One standing in front of the kneeling one. He was wearing a vintage suit, his appearance youthful and radiating powers. After waiting for some time but to hear no response, he continued.
"Mental pollution, such a long time since I have seen someone be suffering to this extent, unlike me."
The kneeling one's silhouette broke down in to shards before reassemble into that of a girl, Ina. The shock from having her mental space scrambled prevented any form of registration of reality. She could not even differentiate the thoughts belonging to her and the thoughts belonging to the man in front of her.
"But this is enough to fool the one backing you. See you around."
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"You ... There is something different. This smell, this flavor, this is only possible if ... So you are their only frontliner, All Might?
Spoke up All For One, who was turning his back to the arrival of his enemy. He was gauging the attacks of the Meta Liberation Army on the single black airship. The stage was being constructed and he let it be. The future could only be divined and be scried if put in conjunction with the entire world so by limiting the stage to this extent, they were betting on the randomness of the natural order.
Surveying the receding coastline of Japan, All For One sent the signal. On land, the remaining force of the Meta Liberation Army teleported to the notable heroes stronghold and known military bases to ravage the place. Their first target was UA, the hero highschool now was a flying fortress enough firepower and resources to back the Pro Heroes preparing as back up. The nearby river froze before rising upward, ramming and binding the place.
Inside the marbles containing cities and towns, the spies began to spread chaos all over the population, leading to small-fry heroes fighting insurgency. The streets were immediately filled with chaotic firing of quirks from heroes and villains. This level of attack was not high but spread enough chaos to push the security system to the brink.
A sinister tree, Yggdrasil, took roots and grew tall, supporting the first spatial barrier surrounding Japan's air, sea, and land territory. From the trunks fell waves and waves monsters resembling people but with abnormal proportions. The main core of the tree, the fruit, resided atop the height, inside was a naked man covered in black pus.
"Entertain me."