Author's Note: I first read the concept of Momo Yaoyorozu being Hana Shimura in the fic "Ghosts of Flowers" by juurensha. It's an excellent fic that I recommend. I'm intrigued by the concept of Tomura having the power of destruction and his sister having the power of creation.

Happy Birthday Momo! I decided to torment her by gifting both Tomura and All for One as relatives. What a lucky girl. The gift this time is Grandfather for One instead of Dad for One. Although I stand by my belief that All for One gave Decay to Tomura in canon, in this fic his quirk manifestation was just a random tragedy. All for One doesn't kill his own family.

Credit goes to Silverstarwolfgoddess for this lovely title.

Hana Shimura woke up in a strange hospital years in the future. The Hero Public Safety Commission special agents sent to interview her told her that she'd been found in a capsule inside a villain's laboratory. Apparently she'd been in suspended animation, not aging.

When they interrogated her about the villain who'd decayed her entire family, Hana didn't tell them about her little brother. She knew she ought to be honest with the authorities. The teachers at school always said the heroes were the good guys and everyone should cooperate with them. But all of this had started because she'd tattled on Tenko and blamed him for her crime. She couldn't bring herself to betray him again.

The HPSC also pressed her for details on why a notorious villain would abduct her and keep her in a capsule, but she didn't know. She shouldn't be alive at all. She'd felt the sensation of her body decaying away. Every night, she had nightmares.

Although she'd pleaded for answers, the HPSC did not have any information about her little brother's fate. They promised to add him to the list of missing people, but in a distant way, as if they did not believe anything would come of such a belated investigation. None too diplomatically, someone whispered in her earshot that the boy had probably died with the rest of the Shimura family.

Hana was placed in the witness protection program. Her name was changed to Momo Yaoyorozu. Her new foster parents were extremely kind to her. They'd adored her immediately and spent a huge chunk of cash fighting with the HPSC for the right to adopt her. They were wealthy, with plenty to spend on her therapy and sleep studies. Several different psychologists told Momo that she must have imagined being turned to dust, that it couldn't be real. She'd repressed whatever had actually happened to her out of trauma. Gradually, Momo's nightmares faded to once or twice a month. Her quirk manifested not long after her adoption: Creation, the ironic opposite of her brother's destructive power.

Apparently strong quirks ran in the family. They could have been heroes together. If only everything had been different.

For a long time, Momo struggled with mixed feelings about becoming a hero. She wanted to carry on her little brother's dream, but she didn't feel worthy. It wouldn't be the same without him. Even if the odds were low, she could not shake the hope that Tenko might still live. If there was any chance at all of his survival, he was probably being held by the same villain who'd kidnapped her. Perhaps she could obtain more information by joining the HPSC. But she could not shake the feeling that they were lying to her. They'd paid her visits every year, but refused to even give her the name of the villain who'd both saved her and experimented on her. Momo decided to become a hero in order to launch her own search for her brother. No one except her cared enough to look.

When Momo first saw Tomura Shigaraki at U.S.J., he did not look familiar to her at all. His skin was dried out, and his eyes held only madness. But he'd stared at her as if he'd wanted to devour her alive. His power remined her of her brother—but no, the psychologists all said that she'd imagined her little brother's quirk. It was a coincidence. (It was her nightmare returned to life.)

After U.S.J., Momo had nearly said something to a teacher. But what would she say? That a villain had given her a scary look? She feared they would think her a coward. Maybe she'd imagined it.

A week later, Momo received an anonymous email from an unfamiliar domain. It included a picture of Tenko, except at least a couple years older than she'd last seen him. In the picture, his hair had turned white and he had dead fish eyes. The email threatened her to come to an abandoned warehouse alone, or her brother would die. If she told the heroes, her brother would die. The note finished:

If you have any doubt that we have Tenko, then he said only the two of you know about the time you stole Nana Shimura's picture from your father's office.

Momo's blood ran cold. Only she and Tenko knew the truth of that incident, because she'd blamed her little brother for the theft.

Of course she knew that she should tell her teachers. But she could not bring herself to betray her little brother again. Momo created a bulletproof vest, a taser, and a walkie-talkie, then headed out alone. She was afraid to leave a note for fear the villains might find out. Silently, she apologized to her adopted parents, I'm sorry, Mom and Dad. I have to do this. I owe it to Tenko.

The dust from the warehouse made Momo sneeze. The air felt dry and chilly. Her flashlight cast light across empty metal shelves. She was starting to fear she'd come to the wrong place. What would happen to her brother then? Mixed in with her fear, she felt a twisted hope that she might survive this. Ugh, how disgusting, for her to be thinking about her own life at a time like this. Maybe she hadn't changed despite all her efforts. Maybe she was still a coward who would put herself ahead of her little brother.

No. She had to save Tenko, even if she didn't make it out of here alive. She'd come prepared to hold off the enemy while he ran away. Older siblings had to protect younger ones. Raising her voice, she shouted, "Tenko!"

"I'm here, big sister. Or should I say little sister now?" Tomura's raspy voice cut through the air like a chainsaw.

Momo jumped in the air, swinging her flashlight beam over him. This time, he wore ordinary sweatpants and a sweatshirt with the words: I have two titles, brother and gamer. And I crush both of them.

"D-did you call me sister?" Momo stammered. With her free hand, she reached for her taser.

"Don't you recognize me, Hana?" Tomura's eyes drank in her face like a marooned man finding water. "Your sidekick, the Lieutenant Savior to your Captain Villain Crusher?"

When they'd been children and played Heroes and Villains together, Momo had gone by Captain Villain Crusher and Tenko by Lieutenant Savior. No one else knew those names except the two of them, since they'd played in secret, away from their hero-hating father. With a strangled scream, Momo ran forward and threw her arms around her brother. The taser and flashlight slipped from her fingers to rattle on the floor.

Tomura stroked her hair with gloved hands. "I knew you'd come for me. Grandpa warned me that not all heroic siblings can be trusted, but I knew you'd never be able to abandon me again."

Momo sobbed into his shoulder, "Tenko, I'm so sorry! I never should have blamed you for taking the picture. I never should have stood by and watched while our father hit you. I failed you as a big sister."

"I forgive you." Tomura kissed the top of her head. "You were just a level one, a little kid. You came for me this time."

"I'm so glad you're alive." Momo gazed up at him with wide eyes. "Did you escape your captors? Did they force you to act like a villain? You can tell me later. We need to get out of here." Alarm bells were ringing in her head, but she willfully ignored them. She wanted to believe in her brother. She could not doubt him, not after he'd forgiven her own betrayal. They were the only survivors of their family. She'd promised to find him and save him.

Tomura chuckled. "My poor sister, you've been brainwashed by the HPSC. You don't yet understand how Hero Society destroyed our family. But I'll teach you better. Come with me, Grandpa is waiting."

"G-grandpa?" Momo backed away, finally understanding the danger. Her brother had lured her here with a false threat, and she'd walked straight into the trap. She formed another taser in her hand. But Tomura made no move to grab her. He only watched her with an amused gaze. She stepped backward, toward the exit, afraid to take her eyes off him.

Momo walked straight into a giant man. Looking up, she saw a bald scarred head with life support equipment looming over her. She screamed. His muscular arms fastened around her, energy dancing off his hands. Her eyelids slipped shut as the sleeping quirk took hold. With her last strength, Momo reached out toward her brother. But Tomura only watched as she collapsed.

The whirring of a ventilator woke Momo up. A giant hand rested on her forehead, caressing her hair. With a scream, she sat up.

She'd been lying on a fluffy sleigh bed, her head resting in the lap of the man who'd put her to sleep. She shot backward so fast her head hit the wall. Stars danced behind her eyes. To her horror, she realized her clothing had been changed. She wore a red dress with a very high collar buttoned all the way up to her neck and a corset top. The frilly silk sleeves were buttoned close to her wrists and so tight she could barely bend her elbows. Several layers of underskirts and a long train tangled her legs. Instead of shoes, she wore only stockings. Her hair had been fastened into pigtails like she'd worn as a little girl. She hyper-ventilated, shocked at the violation. "Who are you?"

The villain was even taller than she'd realized, over seven feet. A tube ran down from the mask over his mouth, connecting somewhere under his black suit. An amused smile on his lips, he said, "Most people call me All for One, but you can call me Grandpa. You have nothing to fear from me, Hana. I may be a dangerous man, but I'd never harm you. I'm your father's father. And family is very important to me."

"My grandfather died before I was born," Momo said numbly. She tried to form a weapon, but nothing happened. For the first time, she realized a quirk-suppressant bracelet had been locked tightly on her wrist. Oh, dear, she really should have gone to her teachers for help.

"He's not dead, and neither am I." Tomura entered through the bedroom door. As Momo looked around, she realized this was a very strange bedroom with metal walls, no windows, and a thick door with no handle on her side. Tomura patted her head. She let him, keeping a careful eye on the scarred villain.

All for One said, "You must have a lot of questions."

Momo nodded, unable to speak. On some level, she still couldn't believe this was really happening. Her younger brother couldn't have turned into a villain older than her. She couldn't have been kidnapped by a man claiming to be her dead grandfather. This was another nightmare, a product of her guilt for failing to save Tenko. Any minute now, she would wake up back in her own bed.

All for One took her hand. The two villains sandwiched her. Panickily, Momo thought that his hand felt entirely too real for a dream. She barely had the wits to pay attention as All for One spoke:

"Your grandmother, Nana Shimura, possessed a transferrable quirk that she inherited from my little brother. I initially sought her out under a false identity, planning to get close to her and steal my brother's legacy back. But I became enthralled by her." All for One's voice filled with nostalgia and an undercurrent of something more dangerous. "Nana was a remarkable woman. Always smiling, always caring for others, courageous to a fault. She was the ideal hero, everything I should have loathed—and yet, being with her made me happy. She lived every single day full of joy, as if she wanted to have no regrets. That beautiful spirit intoxicated me. I even temporarily set aside my villainous ambitions and started a family with her. But when she found out my true identity, she took our son and fled."

Frantically, Tomura cried, "Don't you see, Hana? All our problems started because our family split apart. It caused Dad to go insane. If we'd just stayed together, then we would have been happy."

Momo was having trouble breathing. It might be partly panic, partly the tightness of her corset. The aftereffects of the quirk used to knock her out had left her woozy. It took a moment for the room to steady and her to pull enough wits together to ask: "Did you kill Grandma Nana?"

"No, never." All for One shook his head vigorously. "Nana Shimura will always be the only woman I'll ever love. She self-destructed during our fight, desperate to protect her successor who wasn't even her real son. I'll never forgive All Might for taking her away from me."

Momo couldn't understand in the slightest. How was All Might involved in this? Nothing made sense, and her head hurt too much to even think straight. All for One's grip frightened her. She tried to jerk her hand away, but he held on too tight.

"What are you going to do with me?" Momo whispered, painfully aware this was not a dream. She'd foolishly gotten herself into this mess.

All for One smiled. "I'll look after you, of course. As your oldest surviving relative, naturally I'm your legal guardian. You'll have to withdraw from hero school. I can't tolerate my granddaughter being infected with the same madness that killed my brother and wife."

Momo already had two lovely adopted parents. She wanted to go home. But she feared bringing them up. Instinct told her that All for One would not appreciate her considering anyone else to be her family. Because of her stupidity, she might never see her parents again. Tears welled up in the corners of her eyes.

Awkwardly, Tomura scratched his neck. "Don't look so sad, Hana. Grandpa always took good care of me, and he'll look after you, too."

Good care? The last time Momo had seen her brother, he'd been acting like a madman and trying to murder her classmates. She shuddered. The room spun again.

All for One placed a steadying hand on her back. "You can have any toys or treats you desire delivered to your room."

Momo picked up on the most important part: "I can't leave my room?"

"Not until I feel that I can trust you." Steel lurked behind All for One's soft tone.

Shifting from foot to foot, Tomura asked, "Grandpa, can we show Hana the special project? I think it will help her understand."

All for One titled his head, considering. "Very well. Take your sister's arm—she's still dizzy from the side-effects of her slumber."

As Tomura locked their arms together at the elbow, Momo suspected this was more so that she wouldn't run away.

From the outside, it was painfully obvious that Momo's new bedroom was located inside a bank vault. She briefly considered the nightmare theory again. This was all too insane to be real.

The villains led her down a steel corridor, then a flight of stairs. At no point did she see any sign of a window, so running did not seem smart. This place was a maze. All for One pressed his thumb to a scanner, then the door slid open.

The laboratory inside was full of Nomu in tanks. Momo gasped to see the same monsters that had tried to kill her friends. Tomura pulled her close to his chest and shielded her eyes. He half-carried her as they walked forward.

Another fingerprint scanner opened a second, much thicker door. Inside lay a row of glass coffins with glowing tubes attached. The closest coffin was empty. No, on closer look, it had a pile of grey dust inside.

Mostly to herself, Momo murmured, "The heroes found me inside of a container like these."

All for One sighed. "Yes, it happened during a raid on one of my bases. Due to an accident, an empty preservation chamber was removed and you were left behind. Several people died for the error, I promise you. I count myself fortunate that you were nearly ready to be woken up, or the idiot heroes might have killed you by mistake. Ah, but if only you'd woken up a little sooner, then you could have grown up by my side." He eyed her as if longing to steal away her years and deage her into a cute child.

"I was turned to dust." Momo stared at the grey pile behind the glass wall, unable to rip her eyes away. "It wasn't a dream or the trauma talking. My brother decayed me."

"I'm sorry," Tomura said anxiously, clutching her close. She flinched from his gloved touch.

All for One said, "You mustn't blame your brother. It's difficult to control strong quirks when they first manifest. If I'd been present, then I could have stopped him. I would have taught him to use his abilities only against enemies instead of relatives. This all happened because the heroes separated me from my family."

Momo did not know what to say. She did not blame her brother for the accident so long ago. But she could not forgive him so easily for taking advantage of her desire to save him and kidnapping her. Even though she suspected he'd been brainwashed, she couldn't trust him not to hurt her. Her temples throbbed. Everything was a jumble in her head, and she didn't know what to think, except that she wanted to go home to her parents, not stay with these villains. It did not seem likely she would get her wish. She'd always relied on her powerful quirk. Without it, she didn't know how to fight back. She was just a helpless teenage girl. And her head hurt so much. If only this would turn out to be a dream. She focused on her biggest point of confusion. "How am I alive?"

All for One said, "I built these chambers to painstakingly recreate you from atoms. It was a labor of years, but I did it all for you, my beloved grandchild." He pressed a cold kiss to her forehead. "Come, see." Taking her hand, he dragged her over to the adjacent coffin. Kotaro Shimura lay inside—or at least, the upper half of Kotaro Shimura. From the waist down, he was gone. There was no trace of blood, just particles floating around under the glass. Very, very slowly, his body was reassembling itself.

Momo gasped and put her hand over her mouth. This definitely couldn't be real. Maybe she'd been hallucinating ever since she'd been knocked out. Her head spun. The entire room blurred.

All for One said, "I'll do anything for family. I've saved your father for you. When he wakes up, I'll make certain that he's the ideal father. He won't be able to hurt you, only love you unconditionally. As for you, my dear granddaughter—I don't think we need to mentally adjust you just yet. You're still a child. I'll give you time to adapt on your own."

Momo trembled, picking up on the threat. If she didn't at least fake compliance, then she'd be brainwashed. If only she could think straight. She swayed.

Tomura caught her. "I know it's a lot to take in, Hana. But our family will be together again! Grandpa wasn't interested in resurrecting Mom or our maternal grandparents, but I persuaded him. If I bring back enough achievements for the League of Villains, then he agreed to bring our entire family back to life."

Ah, so this explained the extra coffins. Momo did not know how to feel. Of course she desperately wanted to hug her mom and grandparents again. But what did it mean for Tomura to bring back achievements as a villain? Would he buy each resurrection with the deaths of her friends?

Lips moving, Momo counted. "One, two, three, four, five coffins. Dad, Mom, Grandma, Grandpa. Who's in the fifth coffin?"

All for One's eyes lit up. "Ah, my longest project. Come, gaze upon the beautiful face that you've only seen in pictures." He tugged her over to the fifth coffin.

Nana Shimura lay inside, her eyes closed and her arms across her chest. She looked pale as a corpse, her lips starkly red against her cheeks.

All for One cried. "Is she not more beautiful than any photo?" He pressed a kiss to the glass lid, right above Nana's lips. "That buffoon All Might will be so astonished. Especially after I program his former mentor to rip out his heart when he hugs her. The last thief of my brother's lineage will be gone. If my calculations are correct, I should be able to use my dear wife to take back my brother's quirk. Then my family will be complete." His voice rose to a crescendo as he placed his cheek against the glass coffin. "My darling love, you'll be mine and only mine for the rest of eternity."

It was all too much for Momo to bear. She collapsed to her knees, tears of despair falling from her eyes.

Tomura knelt down and pulled her into a forceful hug. "Don't cry, Hana. Grandpa says I'm the big brother now, because I'm older than you. That means I'll protect you forever."

There was no reasoning with his madness. Momo sobbed, surrounded by the corpses of her family and two living family members who would make her wish she was dead.

OMAKE TIME!

Omake: How to Transfer One for All

All for One: Since my little brother passed on his quirk by sleeping with the Second holder, clearly I can get it back by seducing one of his successors. However I didn't find any of them attractive until Nana.

Hikage: Lies, he tried to seduce all of us. Why do you think I ran off to become a hermit in the forest?

Years and one child later:

All for One: I'm starting to think One for All is not transferred by having sex. However, my wife is hot so I'm going to need to keep experimenting in case one of these days it works.

#AFO probably: Babe, can you dress up like Captain Hero next? Maybe costumes are necessary for the transfer process, and I'm certain my nerdy brother tried that at least once. #Nana: Haha, you don't need excuses for your kink.

#

Omake: Fateful First Date

All for One: I have very strong family values.

Nana: Wonderful, I'm looking for a husband who will stay at home with the children while I focus on my career.

All for One: Fortunately I have minions to do all the housework while I'm busy with being your archnemesis.

#

Omake: He's Got His Priorities in Order

Tomura: Please can I bring the rest of my family back to life, Grandpa?

All for One: I dunno, I don't have enough bank vaults for all of them.

Tomura: But you have over a hundred bank vaults!

All for One: They're all full of my demon king merchandise.

Tomura: You could buy a new bank vault.

All for One: Whenever I go out shopping for vaults, I always end up buying more demon king merchandise too. It's an uncontrollable cycle.

#

Omake: Playing with His Dolls

All for One: I'm going to buy my granddaughter a gift after kidnapping her. Girls love frilly dresses.

Momo: You changed me in my sleep. What the hell is wrong with you?

All for One: That's just what your grandmother always used to say.

#

Omake: The Totally Canon Omake

Momo: Brother, I'm surprised Mon-chan wasn't in the fifth coffin. I know how much you loved him.

Tomura: Actually Mon-chan woke up a few weeks before you.

Momo: Did you bring your dog back to life before your family?!

Tomura: For your information, Mon-chan is the only family member who didn't let me down. Maybe you shouldn't have blamed your crimes on me.

Author's Note: It didn't come up in this fic, but I like to think this is an Inko Shimura AU and All for One is also Izuku's grandfather. Momo needs a cousin to rescue her from the vault.