Author's Note: Happy Birthday, Spinner! Since I was excessively kind in my last birthday fic, today's giftee will be the recipient of all my pent-up angst.

Thank you to the wonderful people who stepped up when I requested birthday ideas for Spinner: RianMoeru, makeshift_moth, MelancholysSunshine, grimalkinmessor, and MaxiemumDamage. I dedicate Spinner's suffering to you. Some of the ideas I didn't use this time, I'm saving for future birthday gifts—Tsuyu would also be a great fit for the backstories that people sent me.

Spinner gazed hopelessly at the glass walls around him, twice his height and enclosed on top. The giant terrarium had artificial flakes across the ground, imitating dirt but soft and unable to stain his pajamas. A fake tree trunk rose up the middle, hollowed-out with a bed and a heating pad inside. The only privacy he had, not worth much since there was no door to close. A fake rock with a hole in the middle formed a shallow bathing pool, although Spinner would die before he bathed out in the open like an animal. It didn't matter that this place had hidden cameras everywhere. It was the principle, the sting of the casual insult not even intended. Another artificial rock pile in the corner was made of squishy, soft material for climbing. Flowers and a Mahogony fern grew along the ground and down the tree trunk. To the naked eye, it looked natural, but a closer look would reveal flower pots full of dirt. Moss sprouted from several ledges running up the walls, comfortably positioned beds under the giant sunning lamp overhead. Spinner didn't know why All for One bothered with the illusion of real outdoors. They both knew Spinner would never see the sun again.

(He didn't think of himself as Shuichi Iguchi, that fake name, or Number Eighteen, his birth name. Spinner was the name he'd chosen for himself.)

At the sound of movement, Spinner drew his knees up to his chest. He did not bother to look up.

Tomura Shigaraki's body walked into the room, but Spinner knew All for One lived inside. All for One had cut Tomura's hair short and styled it to resemble his old body. Perhaps at least one of his many quirks came with a skin care regime, because his lips had gotten less chapped. The old scars on his neck had healed. Tomura had never liked suits, but All for One always wore a black suit with or without his overcoat. Even the smell was wrong—Tomura never would have worn cologne. Every single time, Spinner hated to see his friend's body puppeteered around under another's control. In the early days, Spinner had begged and pleaded for Tomura to fight back. He'd reminded his friend of all the good times playing video games and of their noble cause. Later he'd tried to provoke a reaction by needling at Tomura, offering deliberately bad gaming takes and using all of Dabi's old insulting nicknames. As a last resort, he'd begged for help, because Tomura had always been weak to pleas from his friends. Nothing had gotten even the smallest twitch of a finger. All for One had laughed and said he'd eaten Tomura's consciousness. (Whatever the hell that meant, it sounded very bad.) Spinner hadn't wanted to believe it, but he could not remain blindly optimistic in the faith of all the evidence that Tomura was gone forever.

Before entering the terrarium, All for One checked the temperature and humidity settings outside. (Like monitoring a pet, Spinner thought bitterly.) Then All for One teleported past the glass walls.

All for One had stolen Kurogiri's quirk before ripping the Nomu in two. Kurogiri had defied his programming and tried to fight, for Tomura's sake. His pitiful resistance had not lasted long.

Footsteps approached Spinner. He didn't look up. His nails dug into his pajama pants and he buried his face in his legs.

All for One touched Spinner's forehead, checking his temperature. Despite his best efforts, Spinner flinched.

Kneeling down, All for One asked, "Would you like to play a game today?" A marble danced on his fingertips. All for One had stolen all of the League's quirks before murdering them. Their deaths, more than anything, told Spinner that any bit of Tomura was truly gone.

Dully, Spinner said, "Just kill me already."

"I'd never kill my own son." All for One patted the top of Spinner's head, his hand comfortably heated from using just a tiny bit of Dabi's fire. He liked to show off his fine control over their abilities.

"I'm not your son. Why are you even doing this?" Spinner looked up, wanting to see the expression on All for One's face when he answered. He desperately needed to know why he'd been trapped in this living hell.

Spinner had been created in a Nomu laboratory. Dr. Garaki had used All for One's DNA to create the latest in the number series, without permission. The doctor had died for that offense, at least after All for One had realized it.

As a small child, Spinner had escaped the laboratory. Life in foster care had been…difficult. When Spinner had first joined the League of Villains, he hadn't realized the organization's connection to his past until he met Dr. Garaki for the first time. Then it had been too late to walk away. Spinner understood clearly that villainous organizations didn't let people just leave with information about their locations and their member's quirks. So Spinner had kept his head down and hidden his true power. His ability to cling to walls was merely an aspect of his gecko mutation. Spinner had been genetically engineered as a multi-quirk Nomu, using All for One's DNA as a basis to create a being capable of holding infinite quirks without suffering any mental damage. It was a passive ability. All for One would never have noticed if he hadn't carelessly decided to stuff Spinner full of quirks during the League's final stand. Then All for One had felt Spinner's unique quirk and detected the similarities to his own. He'd quietly run a DNA test. But first, he'd stolen Spinner's quirk, which had allowed the villain to perfect Tomura's body, turn it into the ultimate weapon, and completely take over. Spinner would never forgive himself for that.

Still touching Spinner's head, All for One said, "You share my DNA. That makes you my family, and that's why I protected you and saved you despite your rebellion against me. I seem to be cursed with rebellious relatives."

"Stop!" Spinner pushed the warm hand away. "Stop using his fire! If you're pretending to give even half a damn about me, then why do you keep throwing my friends' deaths in my face?"

Despite his superior strength, All for One let go. He regarded Spinner with half-lidded eyes. That cooly analytical expression did not belong on Tomura's face. It was unnatural. All for One said, "I thought it might comfort you, to see your friends' quirks again. You needn't blame yourself for their deaths. Even if they hadn't tried to defend you, I always would have needed to kill them. They were more loyal to Tomura than me."

Spinner shuddered. His stomach heaved, threatening to throw up. He had no idea if All for One meant his deluded words or if this was all a veiled taunt. Perhaps All for One himself did not know. The line between love, hate, possession, and entertainment had always been blurred with All for One. Only All for One's strange obsession with blood family had kept Spinner alive. Spinner suspected he'd just conveniently come along when the villain needed a new toy. All for One had conquered Japan. But Garaki and Gigantomachia, the closest people All for One had to friends, had died. His greatest enemy All Might had also died. What then did All for One have left? The pitiful attempts at resistance from the few surviving heroes could hardly entertain such a powerful being. So All for One's new hobby had been sticking Spinner in a cage like an actual gecko and occasionally poking him with a stick. Spinner felt more like a pet than a son.

All for One was a busy dictator and lost track of time easily, leaving weeks and sometimes even months between his visits to the terrarium. Spinner longed to have the villain gone more than he wanted relief from his solitary confinement. As a former shut-in, he was used to being alone. He preferred the company of Tomura's ghost in his head compared to his friend's living corpse.

Spinner growled, "Tell me what I have to do to make you leave." He avoided looking at Tomura's stolen face. He'd play games if required. He'd even chase after the marbles like a dog playing fetch. He had no fight left, and no one left to betray with his compliance.

All for One clapped his hands. "Today, I brought a gift for you, my dear child. You haven't talked about Stain yet. That's unusual."

Spinner growled, "Stain will find you and kill you."

The League of Villains was dead. Japan's government had fallen. The entire world offered tribute to All for One instead of fighting him. Though there were rumors of the Ninth One for All holder surviving, Spinner had no trust in heroes. So when he'd first been thrown into this glass cage, he'd banked all his hopes on Stain hunting All for One down and taking off his head. It was a very, very tiny hope. Spinner didn't even know if Stain had survived the Tartarus break. But it annoyed All for One to no end when his "son" praised another villain more than him. For an ancient super-being, he had a very fragile ego. Spinner had leapt on his only means to strike back at his captor, praising Stain at every opportunity. At least until even taunting the man he hated took too much effort. Now Spinner didn't even bother to raise his head as he tossed off a half-hearted jibe.

"You've threatened me with Stain so many times. I confess I never took you very seriously. I didn't think that D-rank villain would have the nerve to attack me. But guess what? You were right!" All for One laughed. (It sounded too much like Tomura's laughter. This was even worse than when Spinner could tell them apart.) "The lowly insect dared ambush me, growling about how I'd murdered his precious All Might. I'm surprised All Might even had any fans left after he died so pathetically on live television, quirkless and withering on his back unable to rise like a turtle."

Spinner's head shot up in surprise. He caught All for One's look of triumph at having provoked a reaction. Quickly, Spinner lowered his head again. He told himself that it must be a lie. All for One had grown bored and wanted to play around with his pet's emotions. Sarcastically, Spinner said, "I suppose you defeated Stain in an epic battle. Even if I don't ask, you'll tell me all about it. Why would I possibly believe anything you have to say? You lie so often you can't even distinguish the truth in your own mind."

All for One chuckled. "I knew you'd react like that. Cynicism runs in our family. That's why I brought you back a trophy."

With a snap of his hands, another portal appeared. All for One pulled through a life-sized grey statue of Stain, his blade raised and his face frozen in a snarl.

Spinner sprang to his feet. He wanted to call this another deception, but he'd seen All for One use the petrify quirk before—when the villain had turned Toga to stone in mid-transformation. He'd begged All for One on his hands and knees to turn her back, promising to be the perfect obedient pet for the rest of his life, but when the villain had removed the power, Toga had been completely brain-dead. It turned out that petrification destroyed all higher functions of consciousness.

All for One propped Stain's stone body against the glass wall. "I never understood the appeal, but this fool was your obsession, and now you can keep him. Never say I haven't done anything nice for you, son."

Spinner opened his mouth, but no scream came out. He did not even have the energy left to weep. His last hope was gone. With it went the tattered remains of his sanity.

OMAKE TIME!

All for One: Finally, I have a son who became a villain. This is my dream come true.

Spinner: Stain is my idol.

All for One: HOLD UP! I will not tolerate being upstaged by a loser like Stain. My son is only allowed to join my personality cult.

#

All for One: I ate Tomura.

Spinner: I assume you mean that metaphorically. There's still a chance to save my friend.

All for One: Nope, I meant it quite literally. I eat quirk ghosts in living in my brain, and it turns out I can eat people whose bodies I possess, too. Why are you looking at me like that? Geckos eat other geckos. I thought you'd understand.

Spinner: I can't even summon the will to care about your racism because I'm too freaked out by your cannibalism, and that's a sentence I never thought would leave my mouth.

#

All for One: Yes, I killed all your friends, but look at the bright side—I can use their quirks better than they ever could.

Spinner: How is that the bright side?

All for One: It's better for me, and that's all that matters.

#

Spinner: Toga is my last surviving friend, and I will do anything you say if spare her life.

All for One: Deal, I've removed petrification.

Spinner: …She's brain-dead.

All for One: Yeah, that's what petrification does. She's still technically alive. You didn't specify that you wanted her able to feed herself or piss without a catheter. I've fulfilled my half of the bargain. Where's my hug?

Spinner: I will hate you until the end of eternity for this.

All for One: Breaking your promises, I see. You got your dishonesty from my side of the family!