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“Fuck…” Katsuki groans as the bone goblins pick themselves up. “Don't you losers know when to quit?!” The goblins’ normally fatal injuries crunch closed, fusing into new layers of bone growing over their bodies in flaky layers.
He can see now why this mission was chosen for him. The promise of a lighter penalty was only bait so he’d consent to doing this for the Hero Association. If he pulls this off, the drug trafficking will be knocked down to possession. Instead of three grueling years of only receiving half pay, it would be another six months after this.
Unfortunately, the monsters here care little for Katsuki’s plight, or anyone else’s. Apart from Katsuki, the only other survivors of his dungeon party are Izuku and Tenya, two old friends he hoped he’d never see again. Last they met, those two were bound for the Dungeon Hero Academy, while he was forced to follow his family’s footsteps into a career of crime.
Katsuki holds his shield gauntlets up in time to block an attack. It funnels the goblins onto the other party members. One leaps toward Izuku, but when he pulls the trigger, it clicks on empty. “Cover me!”
Tenya’s legs blur as he bursts through it, exploding the goblin into chunks of bone on the floor. Steam rises from the cartilage funnel growths protruding from his calves. “I got you!” Another lunges at Izuku, and he kicks it in the head. The creature whimpers as it sails through the air and into a stalactite sticking from the floor. Still out of ammunition, Izuku cowers behind Katsuki and crouches onto his knees. He flips his shotgun upside down over his leg. With shaking hands, he thumbs six more shells inside.
Katsuki watches the readings of the shields’ heads up display, monitoring how much sweat has been accumulated inside their mechanisms. As the goblins bang on his shields, more and more of his explosive sweat seeps inside, collected through his bodysuit. “Would you hurry the hell up?! You’re hiding behind me like a coward!”
Izuku’s gun clacks as he finishes reloading. “Okay, okay, I’m ready. Let one through!” When Katsuki and Tenya step aside, he fires. The shotgun’s spread shreds into the goblins’ bony exterior, exposing the meaty insides.
Tenya swings his foot into one of their chests and the muscles splatter up to his knee. Its limp body falls to the ground. “One more down!”
The last two make a valiant charge, but Katsuki smirks at the shield’s heads up display. “It’s finally full. I’m gonna show how I earned my nickname!” Pointing one of the porous shields at the goblins, their axes harmlessly bounce off. When he presses two buttons at his wrist in unison, the mechanism activates. The accumulated pool of sweat in the thin reserve tank is ignited through the shield’s holes. The air is stained with hot smoke and the goblins are knocked onto the ground.
Izuku shoots through one’s head. Meanwhile, Tenya equips his shortsword, and plunges it through the last creature’s throat. The new silence is scarier than the clatter of the battle, which had killed the other half of the party.
Tenya spins three sixty degrees, scanning the dark cavern for any other threats. “I think that was the last mob. What has it been now, two or three miles?”
Katsuki stretches an arm over his shoulder. “Sounds about right. For me, that’s just a warm-up. When I was running dope across the rooftops-”
“Right.” Tenya grunts as he adjusts the black rims of his glasses. “When you were selling drugs. While we worked our asses off at the academy! All the Association cares about anymore is-”
Midoriya interrupts. “Are you seriously still arguing about that? We just watched three people die!”
“Anyway. We shouldn’t be arguing about anything right now.” Tenya runs ahead, sticking to the walls of the cathedral like tunnel. “I’ll scout for the boss. I’ll get to you when I find it.”
Katsuki paces the space, stepping over the bodies. He eyes his surroundings for any unclaimed items, but everything looks the same. Sharp, pointed bits of rock and stalactite sprout from behind the jumbled mess of lost machinery. Cables hang and cross like spiderwebs. Protruding gears still turn, groaning, powered by the magic of the dungeon possessing the space. In all the mess, no loot waits unclaimed, for now. His search is met by the irritating voice of Izuku.
“H-hey, let’s keep looking around in case we missed any items while Tenya looks ahead. Maybe the boss isn’t showing up because of that.”
“Christ, I hope not. Last thing we wanna do now is scour the past few miles all over again.”
Katsuki wanders through the tunnels, and Izuku follows. As they march onward, the lighting fades into near darkness.
Izuku hesitates.
“Come on, quirkless, don’t be a pussy!”
“Come on, don’t to talk to me like that. I’m not like back then..! While I was at the academy, I met a hero who-”
“You two and your fucking academy. It doesn’t take a school to learn to handle guns.”
Izuku’s fingers grip the handle so tightly they turn white. “Do you have to swear every sentence?”
“Shit, shit fuck, ass, hell-”
“Okay, okay! I’ll shut up!”
Katsuki chuckles as he kicks something in the dark. “Just like old times.” The object he kicked begins to glow pale blue.
“An item!”
“Correction. My item.” Katsuki picks up the blue orb. “It looks like some kind of egg. Maybe it’s the last item.”
Izuku kicks at dirt on the ground. “I hope so. I wonder when Tenya is going to…”
Katsuki feels a gust of wind behind him. “Well, there he is.”
“No! Look out!”
Katsuki ducks, and a red blur twice his size swipes over his head.
The creature bounces off of the cage floor with springy, muscular legs. Each ends in a lobster claw snapping at the closest prey. They clack against the stone, echoing through the tunnel like firecrackers.
Every time the legs make impact, they push against the ground, hurling the bulbous torso into the air again.
The head’s jaws split apart like petals of a flower. One of the claws bounces toward Izuku, and Katsuki tackles him out of the way with less than a second to spare.
“Come on, you idiot! Run!”
They sprint together into the darkness. His right shield is still refilling from when he helped finish off the goblins, but the left still has enough sweat inside to fire.
I need to find the thing’s weak spot. I’ll kill it in one strike!
Izuku huffs and puffs, slowly falling behind. His white scarf flaps behind him like a white trail of smoke. “What kind of boss is that thing?!”
“I’ve never seen one like that!” Katsuki slows enough to stay by his side. “How many shells left?!”
Izuku holds up five fingers. “I have a last resort, but I was told not to-”
“You’re already too slow! Save your breath!” Katsuki dodges another claw with a leap. On the way down, he slams his shield into the rough material. A large crack runs down the side of it to the wrist.
Izuku waits for him to catch up, and shoots at the new wound. White fluid leaks through the shattered shell. It recoils, and half of the claw falls onto the floor. With a horrible screech, the boss monster uses its two other spring-like legs to leap again. The broken claw lashes towards Katsuki too quickly to dodge.
“Die!” He pulls the left shield trigger at the moment of impact. Before the shield can buckle under the sheer weight and force, the nitroglycerin ignites. With the holes shattered, the explosion is out of control. The smell of cooked seafood permeates the air as the eruption envelopes the entire claw.
Izuku cheers. “Two more!”
Katsuki groans as they start to run again. The shadows at the edge of everything maintains the illusion that the place is endless. “Where the hell is Tenya?”
Dust is kicked up by Tenya’s steel boots as they clatter down the tunnel, from behind the boss. As he takes it by surprise running past, he drags the sword deep through one of its mangy, furred legs the claws decorate.
It stumbles, but stays upright. Katsuki glances at the legs’ points of contact with the floor with more scrutiny. “There’s little spikes in the fur supporting its weight!”
Tenya nods. “Izuku, tuck your knees!
“Wh-wha?!”
Tenya sprints behind Izuku, and ducks in the next step. “Hold tight to that gun!” He drops the sword, and grabs Izuku’s calves. A leap forward dodges another swinging leg.
“What are you doing?” Izuku’s eyes overflow with tears, but he keeps a firm grip on the shotgun.
“I’m getting you closer to the boss!” Tenya huffs from the extra weight, “Keep an open eye for a weak spot!”
Katsuki drops the needless weight of the broken shield. “I guess it's back to basics for this hand! His scarred, blistered hand crackles with light. “Come at me!”
Its head’s petals of flesh blossom open. An acid coated tongue licks rows of razor sharp teeth clean from past victims. It screams again as Izuku shoots a chunk out of a portion of leg holding it upright. His stomach clenches as his back bounces against Tenya’s at a breakneck pace.
“I’m gonna puke if you don’t-” He quickly closes his mouth as the nausea reaches its peak.
Tenya laughs. “Good shot! Just two more legs, buddy!”
The creature bounces into the air. Still queasy and upside down, Izuku almost doesn’t notice a second mouth hidden in between the three legs. “Weak spot!”
Tenya’s speed is bogged down by Izuku’s weight. Sweat soaks his clothes. “Where is it?!”
“Between the legs, bottom of the hea-” Izuku’s stomach gurgles from the bumpy ride. “I’m gonna hurl-”
“Okay, shut your mouth! No puking!!” Tenya picks up the pace to strafe around the boss. His sword still lies on the ground in Katsuki’s area of operation.
Meanwhile, Katsuki struggles to keep up the pace. He punches at and erodes the claws with his explosions, but only small cracks have been drawn. Nothing like the broken half claw. He jumps and weaves through the air, narrowly dodging again. The clacking shut of the claw is like a thunderclap in his ears.
I can’t keep going like this!
His forearms swell and crack. As he weaves through the entangling legs, smoke billows from his pores. His shoulders ache and creak from the forces of his explosions. The monster is relentless, constantly twisting, turning, and bouncing from wall to wall as it chases them. It twirls like a cyclone as it untangles its legs in the air. Another swing, and this time Katsuki is too slow to dodge the open claw.
Izuku shrieks from Tenya’s back. “Kacchan!”
The pincers tear through his leather armor. He clutches his aching stomach. Blood runs down his pant leg. “No, I can’t die like this…”
He looks down to Izuku, who falls to the ground from Tenya’s back.
“You quirkless idiot…” He coughs, and blood dribbles out of his mouth in a line of drool. “Running around dungeons with a gun, like it’s enough to… save you…”
Izuku’s eyes flare with ultraviolet light, and his scarf floats in the air. “Kacchan! I’m coming!” Sparks of static grow from inside his veins. His muscles distort, and in a single leap, Izuku closes the gap between himself and the root of all three of the boss’s legs. The mouth hungrily snaps at him as he takes a handful of the sharp quills and fur. It jerks up and down, then left and right, but Izuku stays on. With his free hand, he lands blow after blow against the underside of its head. “I’m going to kill it, and you’ll be okay! We can do this!”
Explosions fly from Katsuki’s body as the pincers’ grip becomes tighter. “Are you fucking kidding? You’ve had a quirk this whole time?!” His skin aches, but he continues to ignite his sweat. All the years of memories he’d hoped to keep buried flash before his eyes. He wonders how hard it must have been for Izuku not to laugh, all those times he was playing the victim.
Izuku’s punches continue, and soon its movements grow more sluggish. The bouncing stops, and the creature collapses. “This isn’t the time to argue! Please… Please keep fighting..!”
Tenya picks up the sword, marching proudly toward the prone monster. “You help get Katsuki loose.” His usual mask of stoicism is betrayed by a bloodthirsty smile. “I’ll finish this thing off, and we can leave this horrid place right away.”
Izuku drops to his knees beside the claw still squeezing Katsuki to death. His arms glow again, and he pulls at it. “Push from your side!”
Despite the agonizing pain coming from his stomach and spine, Katsuki manages to push as well. The shell crackles beneath Izuku’s fingers as it finally pulls loose. Katsuki collapses to the floor. With the boss gone, the dungeon begins to fade away.
The tangled power cables, gears, and ancient machines of the dungeon shrink away into the jutting rocks of the cavern. The cavern, then, fades away and the dungeon has completely disappeared. The only evidence left in the abandoned subway tunnel is the scattered dead bodies of the dungeon party. Katsuki shakes as he lies on the cold steel of the rails.
Izuku pulls off his shirt. “Hang on, I’ll-” As he reaches toward the wound with his tunic, Katsuki pushes him away. “Your Quirk- you had a-”
“That’s because no one is allowed to know. And every time I use it, tch!” He winces in pain. “There’s a high chance of the Quirk killing me if I use it. It damages my nerves every time.”
Katsuki’s stomach throbs. It feels like a knife twisting and pulling without any end in sight. He grits his teeth, and he notices people. A team of medics rushes towards them from the distance. Their flashlights dress them in yellow light.
“Why use it for me? And what about Tenya? He-” Katsuki coughs into his arm. Specks of blood speck all over his burnt arms. He tries to see where it landed, but the swollen redness envelopes his entire forearm.
Izuku turns to wave down the medics as they come close. “He’ll have to keep quiet, too.”
Katsuki stares into Izuku’s face, perplexed by the sudden change in his demeanor.
Did the Dungeon Academy really change him this much? Is it even the same person?
Images of their childhood flash through his mind. Why was it so easy to bully him? Sometimes, just the look in his face sends him into an inexplicable anger.
What is it that he has, that I don’t?
The two old friends follow Katsuki as he is lifted onto the stretcher, then carried up the subway stairwell and to an ambulance. Its battery hums to life. Rather than another irksome sensation, the polluted, dank air of the big city is a breath of relief. Izuku sniffles as he watches Katsuki fight for consciousness.
“Anyway I’m sorry I-” Izuku hisses in pain at his nerves. His body tingles, and his glowing veins flicker. “I don’t need to go on the ambulance. I should go now.” He shrieks when, before he can walk away, Katsuki’s hand slaps over his.
Bruised, burnt fingers clench over Izuku’s hand. “No.” He mouths more words, but his weakening voice is too quiet to understand. “It’s fine.”