Miles away in Hosu City, Tensei Iida patrolled the afternoon streets. His aerodynamic hero costume gleamed under the streetlights as he led a small team of sidekicks through the neighborhood's winding alleys.
"All clear on this block," reported Slipstream, a young hero whose quirk allowed him to slide effortlessly across any surface. His green and white costume featured specialized friction-resistant padding at key points. "Pretty quiet today, boss."
"Don't jinx it," warned Pulse, the team's lookout. Her quirk enhanced her hearing within a fifty-meter radius, though extended use triggered migraines. She adjusted her audio-dampening headphones. "I'm picking up normal city sounds, but something feels off about the southern district."
The third sidekick, Blink, nodded in agreement. His quirk allowed brief teleportation—no more than ten meters at a time, with a thirty-second cooldown between jumps. "Been too quiet lately. Criminals holding their breath."
"Stay alert," Tensei said, his voice calm but authoritative. "We'll finish this patrol route, then check the southern district."
They continued their circuit, moving efficiently through the neighborhood. Slipstream glided alongside his mentor, his expression brightening suddenly.
"Hey, isn't your brother competing in the UA Sports Festival today?" he asked. "The one who's got your quirk?"
A proud smile spread across Tensei's face. "Yeah, Tenya's giving it his all. I've got the audio playing through my headset. He's made it to the tournament portion."
Pulse grinned. "Must be in the family genes. Speed, dedication, and those serious expressions."
"Don't forget the hand chops," Blink added, mimicking Tenya's distinctive gesticulation. "Saw him on the obstacle race coverage. Kid moves just like you."
Tensei laughed, about to respond when Present Mic's electrifying voice blasted through his earpiece: "NEXT UP, FROM THE HERO COURSE, IT'S CLASS 1-A'S ENGINE-LEGGED SPEEDSTER—TENYA IIDA! VERSUS THE SUPPORT COURSE'S MECHANICAL MAESTRO—MEI HATSUME!"
"That's my brother's match!" Tensei's eyes widened behind his helmet. He glanced at his sidekicks. "You three go on ahead to check the southern district. I'll catch up in a few minutes."
"Go for it, boss," Slipstream said with an understanding nod. "We know that brother of yours is going to kick ass!"
"Family pride at stake," Blink added with a thumbs-up.
"We'll radio if we find anything," Pulse assured him, already adjusting her headphones to focus on distant sounds.
Tensei watched his team continue down the street before ducking into a quiet alley. He leaned against the wall, removed his helmet for a better view, and pulled out his phone. The screen illuminated his face as he opened the livestream just in time to see Tenya and his opponent taking their positions.
The match began, and Tensei's smile faltered as he watched the pink-haired support student immediately approach his brother and begin... talking? The camera zoomed in on what appeared to be a business pitch, with the girl demonstrating various gadgets while using Tenya as a reluctant model.
"What the hell?" Tensei muttered, wincing sympathetically as his brother became an unwitting advertisement board. Present Mic's commentary confirmed his suspicions—this Hatsume girl was using the match to showcase her inventions to potential sponsors.
Tensei shook his head with a mix of sympathy and amusement as Tenya was dragged around the arena. "Poor kid. Always so proper, he doesn't even know how to handle this."
After several minutes of watching his brother's dignified demeanor crumble under Hatsume's relentless marketing, Tensei decided to send a text to cheer him up.
He began typing: "Watched your match. Remember, even All Might had embarrassing moments early in his—"
A sharp instinct, honed through years of hero work, made him activate his engine quirk. He shot to the side just as something whistled past his ear. A knife embedded itself in the wall where he'd been standing seconds before.
Tensei spun around, helmet still in one hand, phone in the other. His engines hummed at his elbows, ready to propel him in any direction.
"Seems like even fraudulent heroes have good reflexes," a gravelly voice echoed through the alley.
The figure emerged from the shadows—a man with a tattered scarf, bandage-wrapped arms, and an arsenal of blades strapped to his body. Most disturbing was his face: flat and triangular, with piercing red eyes and no nose. A cloth mask covered his lower face, but it did little to hide the malice radiating from him.
Tensei recognized him instantly. "The Hero Killer: Stain."
"You know me." Stain's eyes narrowed. "But do I know you, Ingenium? Beyond the costume and the fame, what kind of hero are you?"
Tensei dropped his phone and slipped his helmet back on in one fluid motion. His engines roared to life. "I'm the kind who's taking you in for the heroes you've murdered."
"Murdered?" Stain cocked his head. "I've merely cleansed society of imposters. Those who call themselves heroes while chasing fame and fortune."
Tensei didn't wait for more philosophy. He launched himself forward, engines propelling him at incredible speed. Stain sidestepped with unexpected agility, but Tensei anticipated this, banking sharply and driving his elbow toward the villain's midsection.
Stain twisted, the blow grazing his side. He drew a serrated blade in a lightning-fast motion, slashing at Tensei's arm.
The hero's armor deflected the worst of it, but the knife's tip found a gap, drawing blood. Tensei pulled back, maintaining his momentum to circle around for another attack.
"Ingenium," Stain called out, tracking his movements. "The Turbo Hero with sixty-five sidekicks. An agency that prioritizes profit over purpose. You're part of the disease infecting hero society."
"You know nothing about my agency or our mission," Tensei shot back, launching another attack.
This time he feinted left before shooting right, his engines giving him the burst of speed needed to land a solid hit to Stain's shoulder. The villain grunted but used the close proximity to swing his blade again.
Tensei felt the sting as the knife sliced across his cheek, breaking his helmet. He rocketed upward, gaining distance to reassess. Blood trickled down his face, but the cut seemed superficial.
Stain flicked his blade, splattering Tensei's blood onto the alley floor. "The true test of a hero isn't how many sidekicks they employ or how many criminals they capture. It's their purpose. Their conviction."
Tensei didn't respond, instead analyzing his opponent's movements. Stain was unnaturally fast, his combat style unpredictable. The confined alley limited Tensei's maneuverability, negating some of his speed advantage.
He charged again, this time aiming lower, hoping to sweep Stain's legs. The Hero Killer jumped, higher than should have been possible, and threw three knives in rapid succession.
Tensei dodged two, but the third pierced his upper arm. He grimaced but didn't slow, using the momentum to slam into Stain as he landed. Both men crashed into a stack of crates, splintering wood flying in all directions.
Stain recovered first, kicking Tensei back and drawing a katana from his back. "You move well, but you lack the conviction of a true hero."
"And you're qualified to judge?" Tensei pulled the knife from his arm, his suit's compression layer already activating to stem the bleeding. "A murderer hiding in shadows, attacking from behind?"
"I am the necessary correction," Stain replied, his voice dropping lower. "The reckoning that hero society needs."
They clashed again, Tensei's speed meeting Stain's blade work. For a moment, they seemed evenly matched—Tensei landing glancing blows while avoiding the worst of Stain's attacks, Stain unable to land a decisive strike against Tensei's speed.
Then Tensei noticed something alarming. His movements were slowing, his reactions dulling. His engines still fired at full power, but his body felt increasingly sluggish.
Stain noticed too. His eyes narrowed above his mask, a hint of satisfaction in his gaze. "You're wondering why your body's betraying you."
Tensei attempted another attack, but his coordination faltered. Stain easily sidestepped, slashing Tensei across the back with his katana. The hero's armor prevented a deep cut, but more blood was drawn.
"My quirk," Stain explained, holding up his blade. "Is the reason why."
Horror dawned on Tensei as his limbs grew heavier. The knife to his face, the cut on his arm—Stain had been playing him, poison maybe?
"You're type A," Stain continued, circling him like a predator. "That gives me more than enough time."
Tensei fought against the paralysis spreading through his body. His engines still burned at his elbows, but his arms refused to coordinate with them. He managed to fire a burst that propelled him backward, buying distance, but his legs buckled upon landing.
"The irony," Stain said, approaching slowly, "is that you're not the worst of them. You at least respond to distress calls, unlike some who only appear when cameras are present."
Tensei tried to speak, but his vocal cords had stiffened. He focused all his remaining control on his right hand, reaching for the emergency beacon on his belt.
"But you've built a business from heroism," Stain continued. "Franchised justice like fast food. Quantity over quality. Efficiency over integrity."
Tensei's fingers brushed the beacon. Just a little more...
Stain's boot stomped down on his hand, grinding it against the concrete. "Your kind dilutes what it means to be a hero. All Might stands alone as the true symbol—selfless, driven by an uncompromising desire to save others."
The paralysis had reached Tensei's chest now, making each breath a struggle. His vision blurred at the edges as Stain raised his katana.
"This is justice," Stain declared, bringing the blade down.
With his last bit of control, Tensei fired his engines at maximum output. The sudden burst threw his body sideways, not enough to escape completely, but enough to change the blade's trajectory.
Instead of piercing his heart, the katana sliced deep into Tensei's lower back, severing his spinal cord.
Pain exploded through his consciousness, then nothing. Complete numbness below the waist. Through the shock and the fading adrenaline, Tensei realized what had happened.
Stain pulled his blade free, disappointment evident in his eyes. "A shame. I aimed for a clean death."
He raised the katana again, preparing to finish the job, when sirens wailed in the distance. Stain's head snapped up, eyes narrowing.
"Boss! Boss, where are you?" Pulse's voice echoed from nearby streets. "I'm picking up your heartbeat—it's erratic!"
"This way!" Blink's voice followed. "I can jump us closer!"
Stain clicked his tongue in annoyance. "Your sidekicks return. Perhaps they'll learn from your example."
He wiped his blade clean on Tensei's costume. "Remember, Ingenium. This is the reckoning. Only the worthy will survive the purge."
With that, Stain sheathed his sword and leapt upward with inhuman agility, catching a fire escape ladder and climbing swiftly to the rooftop above.
Tensei lay paralyzed, blood pooling beneath him, his breathing shallow.
Through dimming consciousness, he heard his sidekicks' frantic calls growing closer. His last thought before darkness took him was of Tenya, still competing at the festival, unaware that his brother's life had just changed forever.
On the rooftop, Stain moved swiftly across the Hosu skyline, putting distance between himself and the crime scene. He'd traveled several blocks when he sensed another presence.
"Impressive work," a casual voice commented from the shadows. "Though you left him alive."
Stain spun, blades at the ready. A figure emerged—a man in a white, featureless mask with eye slits, wearing a tight-fitting black shirt and tan pants. His relaxed posture belied the dangerous aura surrounding him.
"Who are you?" Stain demanded, not lowering his weapons.
"Just an observer." The masked man leaned against a ventilation unit. "They call me Ghost. I'm here as a sort of... goodwill ambassador."
"I work alone," Stain replied coldly.
Ghost shrugged. "Of course. Your crusade is quite personal. But have you considered the broader implications? The bigger picture?"
Stain's eyes narrowed. "Speak plainly or leave."
"Ever heard of the League of Villains?" Ghost asked, his tone conversational. "They're fans of your work. Especially the message behind it."
"I'm not interested in villains or their leagues," Stain spat. "I am the necessary correction to a corrupt hero system. I don't ally with criminals who hurt innocents."
Ghost pushed himself off the ventilation unit. "The League isn't what you think. They're looking to reshape society—not unlike yourself."
"Through what means?" Stain challenged.
"Various," Ghost admitted. "But with a clear target: the false symbol that props up a broken system."
This gave Stain pause. "All Might is the only true hero."
"Is he?" Ghost circled slowly. "Or is he simply the most effective distraction? The shiny object that keeps people from seeing the rot beneath? Sometimes to build something better, you must first tear down the old."
Stain studied the masked figure. "You speak like someone who's given this considerable thought."
"I'm merely a messenger," Ghost replied. "But I recognize kindred spirits. Those who see through the façade of modern heroism."
"And this League? What do they offer beyond philosophy?"
"Resources. Information. Targets." Ghost stopped circling. "Perhaps even a platform."
Stain sheathed one blade but kept the other ready. "I'm listening."
"Their leader would like to meet you. No commitment required." Ghost produced a black card with a number written in red ink. "Just a conversation between like-minded individuals."
Stain took the card, examining it carefully. "And you? What's your stake in this?"
Ghost's mask revealed nothing, but his voice carried a smile. "Consider the offer. The League is moving soon, with or without you. But your presence would add... legitimacy to the cause."
Before Stain could respond, Ghost disappeared into the shadows with unnatural speed.
Stain tucked the card into his bandages, looking back toward where Ingenium had fallen. Perhaps there were more paths to cleansing hero society than his solitary crusade. Perhaps.
But first, he had more false heroes to judge.
Back in the alley, Tensei Iida lay in a growing pool of blood as his sidekicks finally reached him. Slipstream skidded to a halt beside his mentor, horror etched on his face.
"Boss! Oh god, boss!"
Pulse pressed her fingers to Tensei's neck. "He's alive! Weak pulse but alive!"
Blink had already activated his emergency communicator. "This is Team Ingenium requesting immediate medical evacuation! Pro Hero down, severe injuries, location sending now! Suspected Hero Killer attack!"
As they worked frantically to stabilize their leader, Tensei's phone lay forgotten on the ground, the livestream still playing. On the screen, Tenya Iida bowed formally to his opponent, unaware that his brother's blood was spilling across an alley floor miles away.
The camera panned to the scoreboard, updating the tournament brackets for the next round.
Back at UA Stadium, the festival continued its relentless progression. The crowd roared as Midnight announced the conclusion of the match, completely unaware of the tragedy unfolding in Hosu.
In the Class 1-A viewing box, Izuku felt a sudden chill run down his spine. He straightened in his seat, glancing around with a frown.
"You okay?" Camie asked, noticing his sudden tension.
"Yeah," he replied, rubbing the back of his neck. "Just a weird feeling."
Before he could elaborate, the door to the viewing box slid open again. This time, Tenya entered, his posture rigid and his expression a mask of contained frustration.
"Iida!" several classmates called out, their reactions mixed between sympathy and amusement after witnessing his match.
Tenya adjusted his glasses, a hint of red coloring his cheeks. "I apologize for my poor showing. I allowed myself to be manipulated and failed to properly represent our class."
"Don't be so hard on yourself," Yaoyorozu said kindly. "Hatsume's tactics were... unconventional."
"That's putting it mildly," Jiro snorted. "She used you like a walking billboard."
Tenya's shoulders slumped slightly. "I should have recognized her intentions sooner. My brother will undoubtedly have seen my disgraceful performance."
Izuku stood, approaching his classmate. "Your brother will be proud that you conducted yourself honorably. That says more about your character than winning would have."
Tenya looked up, surprise flickering across his features before settling into grateful acknowledgment. "Thank you, Midoriya. That's... quite insightful."
"Besides," Kirishima added with a sharp-toothed grin, "that Hatsume girl's gear was actually pretty cool. Those hover boots? Manly as hell!"
This drew a round of laughter, easing some of Tenya's tension. He took a seat near Izuku and Camie, his posture gradually relaxing.
"Did I miss any notable matches while preparing?" he asked, returning to his usual methodical self.
"Manga beat Shinso," Camie filled him in. "Used his quirk without activating Shinso's quirk—pretty genius."
Tenya nodded, pulling out his phone. After a moment, his brow furrowed. "That's strange."
"What is?" Izuku asked.
"My brother usually texts after my matches. He did for the race and the fortress." Tenya tapped at his screen. "Perhaps he's busy with patrol."
Izuku nodded, but that strange feeling returned, settling uncomfortably in his chest.
"Yeah, I'm sure that's it."