Jin and Rin Bubaigawara clung tightly together from the moment they came into the world. The twin brothers were inseparable. Their mother tried to convince them to wear different clothing, because she'd read online that it would help the twins develop their own identity. The two stubbornly swapped clothing and dressed as closely alike as they could.

"It's fine," their father said. "Twins should be close." His gaze took on a hunger as he spoke.

Under pressure from three people, their mother gave in. She allowed the twins to dress identically and cut their hair the same. Jin and Rin took great delight at fooling other people into guessing their names wrong. Even their mother struggled, because they lied to her when she got it correct. Only their father could always tell them apart. They suspected he might be using some quirk-related means to cheat.

Although their father approved of and encouraged their closeness, he did not treat the twins the same. Jin was praised for being a strong, brave boy. Rin got coddled, cosseted, doted on, and given more expensive presents, but rarely praised for his intelligence. Their mother made up for it by complimenting Rin's test scores and giving Jin more gifts, so the twins did not notice the discrepancy too much.

They lived in a normal suburban house, with a stay-at-home mother and a father who worked some vague business job. They might have continued their normal lives indefinitely, but on their tenth birthday, their mother got into a car accident.

The birthday party ended in a rain of tears, the guests sent home. The twins spent their birthday in the hospital. Their father was too busy talking to doctors to check up on them. They sat next to each other on hard plastic chairs, too tense to look at their phones or talk. They'd never seen their father cry before, but tears fell from his eyes when he returned to tell them that their mother had died.

It was the worst birthday ever.

For a few weeks, their father stayed with them at their house. Then he told them they'd be moving to a safer place. Mania glinted in his eyes.

The safer place was a giant bank vault.

The vault had bunk beds, two computers loaded with games, and a chest of toys. That did not make up for the lack of sunlight and space. The twins put up with it for a few days, believing this a temporary arrangement until their new home was arranged. Jin should have been participating in a soccer tournament next week, and Rin had a trivia competition. When their events passed with them gone, the twins threw an epic temper-tantrum.

Dry eyed, their father waited for them to tire themselves out. Then he told them, "I need you to stay inside, where it's safe. Where you won't die like your mother."

The strange look in his eyes confounded them. Jin stopped crying out of sympathy for their father's pain. Rin stopped crying out of fear.

After a few months of begging, their father finally let Jin out of the vault. Rin had to remain behind, but both twins assumed it would be the younger twin's turn next time.

Jin's father took him into a laboratory full of black bodies floating in tanks. He rambled a lot about rewriting reality and keeping their family safe. Jin didn't understand most of it. Afterward, his father knelt down, patted his head, and said, "From now on, you need to protect Rin."

Jin nodded. "Rin will protect me, too."

"Don't be ridiculous. You're the older brother. That makes Rin your responsibility."

Jin considered this for a moment. No matter how he tossed it around in his head, it didn't make any more sense. "But we're twins." Of the twins, Jin had always been the athletic one and Rin the smart one. However, Jin didn't think Rin would understand their father's words either. Rin definitely wouldn't like it. He was far too proud to appreciate being treated as weak. The twins had always been accomplices, helping each other steal treats from the cupboard or convincing their mother to buy a new game. No one had ever expected Jin to look after Rin. That would have been ridiculous, they'd been born minutes apart.

Their father said, "Rin is weaker than you."

Slowly, Jin said, "Rin isn't as good at sports as me." Their father nodded. Jin continued, "But that's because he doesn't like them enough to train. He always used to play sick in gym class, but he's not actually sick. He's every bit as strong as me. I'd do anything for Rin. But he doesn't need my protection."

Father's smile faded. He grabbed Jin by his shoulders, fingers digging in painfully. "If you don't look after Rin, he might leave you. Do you want that? Do you want him to leave you?" He shook his son.

"No," Jin sobbed, terrified of his father for the first time. His nose filled with snot and tears spilled from his eyes.

Their father seemed to believe Jin was terrified of his twin leaving him. He hugged Jin, then gave him an ice cream before returning to the vault.

When Rin learned he would not get a trip out of the vault next, his fury was legendary. He trashed their room and broke his computer. Jin could not possibly understand why his dad thought Rin was weaker.

Since Father did not replace the computer, possibly as a punishment, Jin let his brother borrow his. He tried to make funny faces and strike poses to comfort his twin. But Rin was in no mood laugh.

"I can't stay here forever," Rin said. "I'll go mad. Please, you have to help me."

Jin had told his father that he would do anything for his twin, and he meant it. Staring into Rin's red-rimmed eyes, Jin summoned his courage to defy their father. "I'll help you escape."

The next time Father came to take Jin out of the vault, Jin dropped a toy in the door to prevent the vault door from closing.

During the tour of the Nomu laboratory, Jin's heart hammered. He wanted to escape with his twin, but he needed to serve as a distraction. Rin's circumstances were far worse. Father would never let Rin out of the vault. But with Rin gone, Father might not even take Jin back to that dark place, since he did not seem to fear for Jin's safety as much. The twins had promised to meet again after Jin could run away too.

When Father checked his phone partway through the tour, then left, Jin had a very bad feeling.

Father returned minutes later, holding up a squirming Rin by his collar. Rin glared defiantly. Father's face had transformed into that of an angry stranger. His red cheeks and snarling lips made him look like a demon. He shook Rin. "You left! How could you leave? You want to run off and die like Yoichi? Is that what you want?"

Who was Yoichi? Jin trembled from fear. He silently begged his twin to give in and appease their father's wrath. But Rin had never been the type to back down.

Kicking their father's chest, Rin screamed, "I'd rather die than stay in that stupid vault! I hate you!"

Howling, Father shook Rin even harder. The sounds emerging from his mouth did not seem human. He spouted out some nonsense language. He'd spoken it a few times before, calling it his old twin language.

Jin ran forward and clung to his father's leg. "Dad, please stop!"

Father gazed down with crazed eyes. "You don't want your little brother to leave, do you, Jin?"

In that moment, Jin made a mistake he'd regret for the rest of his life. He stammered, "N-no, Dad." He'd been so scared, he went along with whatever his father said. He told himself that he needed to appease Father, stop him from shaking Rin more. But maybe he was just a coward who betrayed his own brother.

"I knew it." Father's grin spread wider, distorting his face. "Twins should never be apart."

Then the massive hand with a black hole in the palm swung down, cramming the twins together.

Jin's midsection felt strange and tingly. He looked down. Rin's arm was sticking out of his body. At first, he could not understand or believe what his eyes showed him. At Rin's elbow, his body ended. His hand seemed to be going straight into Jin's stomach. There was a glow where their two bodies merged. That made it seem even more unreal. It did not hurt. Clearly it could not be possible for this to be happening without pain. Jin simply refused to believe it. Not real, not real, not real, chorused through his brain.

Rin looked down. He saw, too. His eyes locked with his older twin's. Rin wailed, long and loud, from terror.

Grim-faced, their father crammed the twins closer together.

Rin slammed into Jin with a sickening squelch. Half his body was gone, and part of his face. The tingles spread all over Jin, like ants across his skin. His twin's screaming was too loud in his ears. He squirmed, thrashed, and tried run, but his father held him too tightly.

Briefly, Rin's eyes locked with Jin's, only a hair apart. Jin would never be able to forget the raw, animal terror he saw there.

Jin opened his mouth to beg, but it was too late.

With one last violent motion, their father forced Rin inside of Jin. Rin's head went in through Jin's shoulder. Suddenly the stimulation was overwhelming. A static filled Jin's mind. He felt like a passenger in his own body. He did not even have the will to scream.

Two fingers and the heel of a shoe stuck out of Jin's chest. He gazed, unable to understand. This could not be real. Not real. Not real. Not real.

Their father grabbed the last little parts of Rin sticking out and shoved them in.

Jin Bubaigawara had voices in his head. He could not stand the sight of his own face. He clowned around to hide a deep pain. As an adult, he lived on the streets as a petty criminal. But one thing had changed from a million other multiverses.

He would never, ever work for All for One.

OMAKE TIME!

All for One: I obtained a quirk to correct my error in failing to absorb my dear little brother in the womb.

Yoichi: I've never been so glad to be dead. My poor nephews…

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Tomura: What happened to you?

Twice: All for One merged me with my twin. (We both hate him.)

Tomura: Would Sensei do that to me?

All for One: Nope, I have no interest in keeping your consciousness around after I steal your body.

Tomura: I might give this redemption DLC a try.

#

All for One: I've finally become the best father ever. I've topped all the other multiverses. I may even run for President of the All for Ones Club.

Author: What did you do?

All for One: What every father wants to do. I gave my son a better childhood than myself. The childhood I always wanted. The childhood I deserved. The perfect happy ending for a pair of twins.

Author: My other characters are going to hunt me down and try to murder me again, aren't they?