Actions

Work Header

Dirth of Depravity

Summary:

Everyone went in knowing Overhaul held no qualms experimenting on Eri, the one supposed to be his own daughter. Turns out to create her, she's not the only one he experimented on.

Notes:

Disclaimer - I don't own My Hero Academia. I wrote this for the Froday monthly challenge for March 2026 where the goal was to write a story based off one of the characters listed on "The Most Hated TV Characters of All Time" list, and I picked the character who is currently number nine, Shou Tucker from Fullmetal Alchemist, hence the plot as my mind instantly jumped to Overhaul experimenting on Eri, who is effectively his daughter.

Chapter 1: Jitsubo

Chapter Text

He threatened Eri’s mom.

Those words stuck with Tatsuma Ryuko as she and the other Pro Heroes looked through the multitude of rooms in the underground Shie Hassaikai base. But peering into one too many rooms with equipment specifically designed for experiments, experiments they knew were likely tied to the small girl and the creation of a drug to turn off Quirks—

If he’s willing to experiment on his own child…

Her stomach churned, bile building in the back of her throat as the more they searched, the more they didn’t find Eri’s mother, and Ryuko’s worry that they wouldn’t find her grew.

But then—

Ryuko opened a door, a door leading into a room of pure white, her yellow eyes taking in the huge bed with pure white curtains hanging down from the canopy, and what looked like a changing table, as two older women sprang into action, glaring daggers at Ryuko.

Who are you!”

How dare you disturb Yaoke-hime’s rest!”

Ryuko frowned, stepping past the two older women dressed in pale blue kimonos that reminded her of ice, eyes taking in the details of the room as a figure stirred in the bed, white sheets draped over them, her eyes focusing in on the changing table, noting the blood staining the white, almost as if purposefully left as some kind of warning.

Are you…” Ryuko asked, feeling one of the two elders attempt to push her out of the room, hissing at her. “Are you Eri’s mother?”

The figure sat up, the sheets sliding down, allowing Ryuko to now see the long white hair that the white sheets hid from view, as well as pale skin, yet—

Ryoko frowned, noting the slight change in skin color, with the skin on her left shoulder and shoulder blade as well as lower torso being slightly paler than the rest of what Ryoko could see, yet as she came closer, she noticed the same kind of paleness to the person’s fingers and face. She looked down, fully expecting to see similar pale scars on the legs, which became exposed when the person sat up, and the sheets fell back.

She didn’t expect…

A blush spread across her cheeks. Wait? They’re male, not female.” She looked over at the old woman trying to block the others from entering, while the other elder tried pulling her way.

Leave Yaoke-hime alone!”

Yellow eyes glanced back at the one—

Ryuko noticed the way their fingers dug into their arm at being called Yaoke-hime and took a deep breath. “What’s your name?”

Their head turned slightly, dulled turquoise eyes now visible, rings of exhaustion under them. They hesitated, swallowed, then, “Chisaki Yaoke.”

Ah,” Ryuko said, turning her head to look at the changing table. “Are there more children? Than just Eri?” A glance back, and Yaoke looked unsure of what to say.

But then, one of the elders—

Yaoke-hime’s given birth to twelve beautiful children so far.”

Twelve children?” Ryuko frowned, fighting back the alarm, but the two older women seemed complicit in whatever was going on. “The eldest is how old?”

Yaoke looked right at her, then said, “Eri will turn seven in December.”

So, twelve children in only seven years?” Ryuko asked, getting no answer from Yaoke, only for a stare, eyes glazed over, while the older ladies chimed in about how amazing and a proper Yamato nadeshiko their Yaoke-hime was. “No wonder you look so tired, but you’re safe now.”

Safe?” Yaoke looked unsure, head turning slightly to the older woman.

Ryuko glanced at the changing table. “Are there any children who are hurt?”

A glance showed a change in Yaoke’s emotion, a look of horror.

Which one?” Ryuko said, tilting her head.

I don’t like the implications,” the elders said. “Of what you’re implying.”

Kai-sama would never harm the children.”

Which is a lie, given he has harmed Eri,” Ryuko thought.

Yaoke’s fingers twisted into the sheets, mouth pressing together before saying, “Gougou and Kosato.”

It’s Toiki now, not Gougou, Yaoke-hime,” one of the elders clicked their tongue, resulting in Yaoke’s eyes narrowing.

And you know Kai-sama was only fixing them.”

Fixing…” Ryuko stared, feeling a feeling of dread set in. “What does

You mean like how he fixed me?” Yaoke said, glaring at the woman closest to Ryuko, a look of utter disgust on their face as they did so.

And when he defeats these Pro Heroes, he’ll fix you again.”

The look on Yaoke’s face—

Whatever this fixing is, Yaoke obviously doesn’t want it,” Ryuko thought. “But what” Her eyes blinked, thinking of how Yaoke referred to one of the children as Gougou, a name one would expect of a male child, only to be corrected to Toiki, the name for a girl. “Please, no. Don’t let what I think to be true, be true.

...

The older women didn’t want to be separated from their princess, didn’t want to believe Chisaki Kai would be defeated. Yet, there was no way Ryuko would let them stay with Yaoke, their male, clear as day to Ryuko, and of course, word came at the same time the other Pro Heroes brought word that they’d found the children.

Ryuko watched the relief wash over Yaoke, as if their nightmare were finally finished. However, something told Ryuko the trauma resulting from whatever Chisaki Kai did to the person in front of her would last a rather long time.

Would you like me to stay with you?” she asked, getting a nod in response, to which she checked in on her trainees and said they would speak later, depending on the outcome as she heard Sir Nighteye was considered in bad shape, before getting into the ambulance with Yaoke as they headed to the hospital, so many questions in Ryuko’s head, questions she found herself terrified to know the answer to, and she stayed with Yaoke as they settled them into a hospital room for examination by the doctors.

The first question out of Yaoke’s mouth—

It took Ryuko and the doctors by surprise.

Am I really male again?”

What?” The nurse, following the doctor, turned a bright red as her eyes drifted down to Yaoke’s groin area, and under normal circumstances—

This might be deemed sexual assault, but

Or something in between?”

What…” the nurse blubbered out. “What is the patient saying even?”

Ryuko took a deep breath, then—

She called it in, requesting that the police run a Rapid DNA test on Yaoke and all twelve of the children, hoping her suspicions wouldn’t be confirmed when she got the results back, but there was no response from Yaoke as the doctor went over the basic physical and noted concerns.