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The world had seen many Quirks: fire breath, super strength, teleportation, gravity manipulation.
But none… none were prepared for this.
Izuku Midoriya. Hero Name: Deku. Quirk: Menstrual Instigator.
An emitter-type Quirk with one terrifying ability: inducing the full effects of the menstrual cycle on any human—especially males. The older the target, the more catastrophic the results.
What began as a tragic mystery Quirk unlocked during puberty became a force of karmic retribution. Its first true victim?
The Mineta Massacre
“Deku, wait! Wait, I’m sorry! I was just making jokes! You don’t have to—AHHHHHHHHHHHHHHHH!!!”
Minoru Mineta curled into a fetal position on the dorm floor of Class 1-A, sobbing and screaming as a tidal wave of invisible pain overtook him. Momo, Jirou, and even Aizawa stood in morbid awe.
“He’s… bleeding?” Jirou blinked.
“Not physically,” Momo replied. “But the pain receptors… he’s feeling every ounce of it.”
“He’s fifteen,” Izuku said quietly, walking away with glowing green eyes. “That’s three years' worth of cycles.”
Uraraka gave him a look that was equal parts disturbed and very intrigued.
All For One’s Crimson Reckoning
All For One loomed over the battlefield, dark energy crackling like thunderclouds. “The stage is set, this shall be our final battle All Might, and the world shall watch as their symbol of peace meets his end by the hands of I, All for One, the greatest criminal mind in—"
“All for One, menstruate.” Izuku stepped forward and snapped his fingers.
All For One tilted his head. “What did that random brat just—AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH!!!”
He collapsed. No, he combusted internally. His centuries of stolen time now betrayed him, condensed into an eternal bleed cycle from hell.
From the Vestige World, Nana Shimura could barely breathe through the tears of laughter.
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The Battle With Lady Nagant (or: Why You Shouldn’t Unlock Vestige #3)
Izuku panted, dodging high-speed bullets from Lady Nagant. He turned toward the screaming voices in his head.
“Bruce! Please! I need something—anything!”
“NO!” the Third shouted. “I’M NOT GIVING YOU THAT QUIRK!”
“I’M GETTING SHOT AT!”
“LET HER SHOOT YOU! IT’S KINDER THAN THIS!”
“BRUCE!” Nana screamed. “He’s our last hope!”
“…Fine,” Bruce muttered. “But I warned you.”
And thus, it awakened: the Quirk once sealed away for generations.
Quirk: Instant-O.
One flick, and Lady Nagant let out a screech so guttural it cracked windows. Her face flushed, knees buckled, and she crumpled in ways no training had prepared her for.
Ten minutes later, the only sound in the ruined city was her ragged screams echoing through broken buildings.
Class 1-A vs. Hormonal Havoc
A few days later...
“Izuku,” Momo said solemnly, “for the good of the class… hit me with Instant-O.”
Kaminari shoved her aside. “No way! Hit me!”
Jirou rolled her eyes. “Idiots. Izuku, you have to hit me with it or I’ll never get any peace.”
“I'm not using Bruce’s Quirk on any of you!” Izuku said, horrified.
Uraraka tackled him. “Totally not for that reason, I swear!”
“YOU CAN’T ESCAPE, IZUKU!” shouted Iida, eyes wild. “WE’VE PREPARED FOR ALL YOUR QUIRKS EXCEPT THE SECRET ONE!”
Bakugo leapt over them all. “Deku, if you use it on me, I’m blowing everyone else up first!”
“…If you fight among yourselves,” Izuku muttered, “I’ll just use it on the winner.”
The next ten minutes devolved into the greatest intra-class brawl in UA history, as every student tried to outfight the others for… reasons they refused to admit.
Epilogue: Tartarus, Twelve Hours Later
All for One, still writhing and shrieking in a soundproof cell, didn’t pause for breath. The security guards rotated in shifts because the audio alone caused mental breakdowns.
"He is still screaming in agony?" Izuku said as he looked at the cell through one of the monitors linked to the camera in All for One's cell in Tartarus, the demon lord was still letting out gut wretching screams of utter agony and suffering, same as he did when being taken here
"Hasn't stopped even for a second yet, must have a quirk to circumvent needing to catch his breath... Young Midoriya, though I'm grateful for your help I think you have made feel bad for that monster, and considering how much I hate him, that's frankly concerning"
All Might sipped his tea beside Izuku in the surveillance room. All Might expressed as though he was happy All for One was suffering for his crimes, after the tenth hour of hearing his pained screams, even All Might was feeling bad for the guy
“I never thought I’d say this… but I almost feel sorry for him.”
“I told you,” Izuku said, sighing. “This Quirk is feared by men for all eternity.
Nana’s ghostly laughter rang out through the vestige space like church bells on a Sunday morning.
Final Note:
Yoichi in the background, curled up like a haunted anime ghost:
"I miss when the worst we had was Danger Sense…"