Chapter One:

All for One stared at the boy tied to a chair. The kid had half-white, half-red hair and an oddly cheerful grin for someone gazing up at Japan's greatest villain. It gave All for One an odd sense of déjà vu. He couldn't figure out why, and it bugged him. He turned to look at his successor. "I thought you wanted to kidnap the brat with the explosive quirk?"

Tomura shrugged. "This one jumped on top of us and demanded that we take him back. Why turn down such an eager recruit?"

Dabi chimed in, "He has an amazing conspiracy theory! You have to hear it! I brought along his cork board."

All for One looked at the board. It was very impressive, with bits of colorful string tying together dozens of photos, doodles, and newspaper clippings. He loved cork boards. "Okay, lay it on me."

Shouto Todoroki beamed. "It's such an honor to meet my best friend's father."


All for One strolled up to the gates of U.A. as if he owned the school, calling, "I'm here to pick up my son."

The teachers readied their weapons and called for the police, but they hesitated to attack—not with the kidnapped Todoroki boy at the villain's side. Although Shouto didn't look or act like a hostage. He was smiling and waving at Izuku Midoriya, who broke through the teachers to run toward him.

Izuku screamed at the top of his lungs, "You told your conspiracy theory to All for One?"

Shouto said, "You can't run from the truth, Izuku. You're All for One's lovechild."

"What truth?" Izuku waved his hands. "You just have a few coincidences and some half-baked claims that we make similar gestures."

"You're waving your hands just like him right now," Shouto insisted.

All for One said, "More like my little brother, actually. You're going to make such a great replacement."

"That does it!" Izuku whirled around. "I demand a DNA test to prove for once and for all that this villain is not my father!"

It amused Nezu, so he agreed.


Izuku gasped. "All Might is my biological father?"

Toshinori's eyes filled with tears. "My boy…I…I had no idea. Though you do have the same hair color as a one night stand from years ago. I only wish I'd been there for you as you grew up."

With moist eyes, Izuku whispered, "You can be my dad from now on." They hugged.

Shouto hung his head. "My theory made so much sense."

"I know you wear a tin foil hat," Izuku said wearily. He whirled on All for One. "But how on earth did he convince you of this? Wouldn't you know if you were secretly my dad?"

All for One shrugged. "He was very persuasive. He had a cork board and everything. I ended up thinking that maybe I'd lost my memories of my secret family after my fight with All Might."

Izuku snorted. "So you're both conspiracy theorists. Maybe we should run a DNA test on you and Shouto next."

Nezu said, "I just did! All for One is the biological father of Shouto Todoroki."

"My father isn't Endeavor?" Shouto's eyes filled with delirious joy. He sniffled. "I've always wanted a dad who isn't Endeavor!"

"I've always wanted a son!" All for One cried. They fell into each other's arms.

"I'm so happy!" Shouto sobbed.

All for One snapped his fingers. "Kurogiri, take us away." Before anyone could react, shadows wrapped around All for One, Shouto, and Izuku, teleporting them to an unknown location.


All for One asked, "How do you like your new room?"

"It's a bank vault," Izuku said.

Staring at the steel walls, Shouto cried, "I love it, Father-Who-Is-Not-Endeavor-And-Therefore-Can-Do-No-Wrong."

All for One wiped a tear from his eye. "Finally, a family member who loves and appreciates me."

Izuku hissed, "Shouto, I understand that you have justifiable daddy issues, but your new dad isn't exactly an improvement. He's the shadow ruler of Japan's underworld!"

Shouto raised his chin. "He's perfect. I love my new dad with all my heart and soul. He has every single qualification that I want in father: not being Enji Todoroki."

Izuku waited. "That's it? That's your entire list?"

"What more could any son ask for?" Shouto cried. "Look at him standing over there, not being Endeavor. I can tell by the lack of a stupid-looking moustache. Can you possibly imagine a more ideal dad than someone who is not Endeavor?"

All for One beamed. "Finally the bar is low enough for me to crawl over it."

Izuku sighed. "I get it, you two are very happy together, but why did you drag me along?"

All for One shrugged. "Plenty of reasons. All Might's brat could be a useful hostage. You still have my brother's quirk. I'd already been planning to kidnap you, so it seemed like a two for the price of one deal. Plus, you look sorta like my younger brother, so I brought this white wig I was going to make you wear while I called you Yoichi."

Izuku recoiled. "What the everloving fuck is wrong with you?"

Holding the wig, All for One advanced. "Just try it on! Your eyes are the perfect shade of green, Yoichi."

Shouto cried, "Dad! You're not allowed to bully my friends."

All for One stopped immediately. "Anything for you, my beloved child."

"It's so nice to call someone who's not Endeavor my dad!" Shouto burst into happy tears again.

Eyeing the villain, Izuku hissed into Shouto's ear, "Please, stop and think about this. Look at the potato head you're signing up for."

"My new dad has a great face."

"He doesn't have a face at all."

"You know who has a face? Endeavor." Shouto's lip jutted out. "Therefore faceless dads are clearly superior."

"He kidnapped you."

"Exactly—the number two hero would be too wimpy for such a lovely gesture. Just look how much my wonderful dad wants to spend time with me."

Izuku said, "At least Endeavor never stuck you inside a bank vault. What does that tell you?"

Shouto tapped a finger on his chin, pondering. "That if Endeavor never thought of them, then bank vaults must be awesome."

Izuku groaned and clutched his head. "Come on, Shouto. I know that you're currently riding high on the thrill of Endeavor not being your father. But at some point, the thrill will wear off. Then you'll still be stuck inside this vault."

Shouto crossed his arms. "The joy of not being related to Enji Todoroki will never wear off! I will happily live inside a bank vault for the rest of my life under the sole condition that my father is literally anyone except Endeavor."

A choked sob came from All for One. He covered his mouth with his hands. "I'm just so happy to finally have a family member who wants to stay in the vault!"

"I love you, new dad who's not Endeavor," Shouto said with shining eyes.

"I love you too, new son!" All for One swept Shouto into another hug and they sobbed on each other's shoulders some more.

Izuku stared at them. "How on earth did this happen? Shouto has a hybrid version of Endeavor and Rei's quirks! It seems biologically unlikely for you to be his father."

All for One shrugged. "I have a lot of quirks. Multiple versions of both fire and ice."

"Yeah, but…did you ever bang Shouto's mom?"

"Izuku!" Shouto cried.

Izuku winced. "Sorry, the question had to be asked."

"I don't recall doing so," All for One admitted. "Give me a moment."

All for One left, then returned with Dr. Garaki. "My doctor has a confession to make."

Dr. Garaki wrung his hands. "I'm sorry. It seemed like such an interesting experiment…"

All for One growled, "I trusted you as my personal doctor, and in return you betrayed me and stole my genetic material."

"It was a mad impulse for the sake of science." Dr. Garaki hung his head. "The number two hero approached me, obsessed with creating a son who had both a fire and an ice quirk. He promised me a huge amount of money. I concluded that the only way to carry out his request was to use a second parent whose body could handle multiple quirks."

All for One said, "In conclusion, you're the test tube baby of me and Enji Todoroki."

"Endeavor…is still my father?" Shouto went white with shock. Then he screamed. Fire exploded from his body, incinerating the vault. The remaining fragments of metal froze and shattered on the ground into splinters. The wave of fire and ice consumed the entire surrounding forest for miles.

All for One said, "He's taking it quite well."


Standing in the smoldering ruins of a villainous base, Shouto declared, "I've made my resolve. I'm going to become a villain. My reign of terror will destroy hero society and sink Japan into the ocean. When I have removed every last bit of evidence of my true parentage from this world, then I will finally lay down and die." His calmness was unnerving. His eyes did not point in the same direction.

"No!" Izuku tackled Shouto. "Death isn't the answer!"

With chilling lack of emotion, Shouto said, "My two fathers are All for One and Endeavor. If it were you, could you live in such a cruel, heartless world?"

As Izuku tried to imagine it, his face paled and his fingers slipped.

"You don't get to judge my murderous rampage—you got All Might as a dad." Shouto marched forward, frost and flames rising off his body.

Izuku gripped his leg, screaming, "Stop! I'll marry you so All Might can be your father-in-law! We'll get every teacher at U.A. to adopt you! You can have all the good dads!"

All for One cupped his hands to his mouth and cried, "Yes, destroy Japan, my son!" He whispered to Dr. Garaki's bleeding body lying on the floor, "I'm so proud of him."


OMAKE TIME!

Dr. Garaki: The quirks merged much better the second time. The first one's personality meshed great while the fire and ice quirks did not.

All for One: First one?

Dabi: (Dancing) It is I, Touya Todoroki! Endeavor, I've put on washable hair dye every single day for years to hide my true identity, all so I can make you suffer and rot before you die by broadcasting this message across all of Japan! MUHAHAHAHA!

All for One: Holy shit, I'm getting intense chills from all the embarrassing flashbacks to my middle school years.

Shouto: Unfortunately, my big brother is an adult.

Later:

All for One: Dabi, I am your biological father!

Dabi: I'm not Endeavor's son? I feel another dance coming on!

All for One: Why do all my kids keep reacting like that? No, due to an unholy experiment by the doctor, you have both of our DNA. But I'll help you kill him! Now, want to prepare a monologue and a convoluted, needlessly theatrical plan to murder your other father, son?

Dabi: Boy would I ever! I finally have a dad who's cool!

All for One: And I finally have a family member who wants to be evil with me! This is wonderful!

Izuku: I don't know if it's horrible or kind of heartwarming.

Shouto: As the person who gets tied to a chair and forced to listen to their monologues, definitely horrible.


Author's Note: The omake I added to this chapter was created by Gfan97, a gifted Dad for One crack writer.

So far, my All for One as a Dad birthday series has been all angst. I wanted to have at least one cracky story, and MaryCipher gave me a great prompt for it. That said, All for One as Shouto's father also lends itself very well to angst, so I wore a second serious version. I'll post that later today. Shouto gets two All for Ones for his birthday, what a lucky boy! (Haha please don't freeze me to death.)