Chapter Text
"Against all the evil that Hell can conjure, all the wickedness that mankind can produce, we will send unto them... only you. Rip and tear, until it is done."
...
Atop the ruins of a skyscraper, a hulking being nearly the same size as the building collapsed, skin and flesh ground down to the bone as it fell with a mighty crash. In front of its decimated face was a man in green armor, who was now running atop its arm to the exposed brain. He drew a sword with a blade of pure red energy which he brought down into the exposed brain. Pushing forward onto the blade's handle with a strained effort, he snapped the blade to keep it within the brain of the titan. As a result of this action blue veins began to glow on what was left of the demon's massive body, ancient magics forcing the demon to remain dead whist giving the user the chance to reforge the powerful weapon. The armored figure jumped back down to the building, walking away as the Icon of Sin fell to the floor, to be removed by ARC scientists before rebuilding could begin. A blue portal opened in front of the man who entered back to return to his home, the Fortress of Doom.
Upon returning the Slayer walked down to the portal, configuring the device to send him once again to Taras Nabad to reforge his Crucible.
"Slayer." The voice of Samuel Hayden rang out, causing the man to perk up to listen. "When you return from Taras Nabad, I will have something important to tell you. The only reason I will not do so now is because you will need your blade for what I am to say." Keeping the man's words in mind, the Slayer set off to reforge his sword, ripping and tearing through any remaining demons in Taras Nabad in a shower of gore and blood.
The quest only took a few hours, as the Slayer picked up another spare battery for his base and dealt with a final Marauder in the underground depths of the ancient city, restoring the blade with little difficulty after that. Upon returning to the base, Samuel Hayden's voice returned.
"Now that you are back, I believe that I found a way for you to return home." The Slayer looked to the mangled robotic body of the man in confusion, causing him to chuckle. "I know you see this world as your own to protect now, but there is no way for them to return. The Icon of Sin has been defeated, and you destroyed the Argent ritual with the destruction of Urdak. That is beside the point though. While you and VEGA were traveling through Urdak, VEGA was able to send through a set of coordinates to an object which would allow you to return to the world you were stolen from eons ago." Beneath the slayer's helmet his eyes widened. "Grab as much as you can carry, Slayer. If you are to embark on that journey, then this will be the last time that you see this fortress." The Slayer nodded, grabbing all of his weapons and alternate suits.
He also picked up the albums he found along his journey, as well as the three guitars on the wall next to his monitor and everything from the wall of collectible statues he acquired. Carry space and weight was not an issue, as an upgraded feature of his suit from his three years within the fortress was the ability to deconstruct his weapons and equipment until he needed it again. He also carried some extra sentinel batteries and cells for the BFG and the Unmaykr, as his world most likely would not have the means to recreate the special ammunition if he were to waste it without his aid. The most important thing he brought with him was the music, downloading all the music he had acquired from his journeys into his suit as it was the one thing keeping him sane during his entire crusade against the demonic invasion.
The ship suddenly darkened, lightning dancing across the walls and screens flashing quickly until another disc akin to the one he brought VEGA to Urdak with floated upwards. The man picked it up, as Hayden's voice met his ears.
"I wish to see the world that created the Slayer. You have done everything possible to save the people of this world and Argent D'Nur, and so I desire to see the world which gave you this ideology."
He walked up towards the now activated portal, as a memory suddenly came to mind.
"They are no longer yours to save."
"I'm sorry!!!"
"W...What are you?!"
"Let's see how long you survive, child..."
The man quickly snapped back to reality, shaking away his thoughts as the portal opened up. The Doomslayer took one last look at the stronghold that he made his home, walking towards the portal to whatever Hayden had described. Upon walking through the portal, the Slayer realized that he was back on Mars, specifically the room where he first reawakened three years ago. He looked upon the sarcophagus he ended up in at the end of the Unholy Crusades, seeing a circular design on the side glowing a bright emerald green.
"A spell designed to send the slayer away from this dimension, to allow the armies of Hell to persist and rule without his interference. Thanks to you killing the Icon of Sin, the persistence segment of this scripture has become invalid. However, the spell still functions as intended." The Slayer ran a gloved finger along the inscribed words, drawing his Crucible blade. The mark of the Slayer shined on the hilt as bright as the circular object, both brightening in tandem before a disk much like the one that he infused to recreate his blade appeared. The Slayer grabbed the disc and held it next to the hilt, causing it to disappear as the red mark became green, the hand guards jutting towards the sides as the blade appeared. It was different than before, with the hilt creating a green portal in front of the man rather than forming a blade.
"No matter what realm he resides in, one truth prevails: Where the Slayer goes, with him comes war, and from the ashes, peace." The Slayer gave the man one last nod of acknowledgement, and stepped into the portal.
...Meanwhile...
"Everyone stay back!" Aizawa Shota yelled, staring down the two villains. It was class 1-A's first day of rescue training. They had been transported to the Unforeseen Simulation Joint with hopes of learning how they might be able to deal with the rescues they will have to deal with in the future, but all of that was stopped by a portal of black mist. Out came two villains, one covered in hands and another of the same mist that they entered in, a separate red portal opening up to reveal what could only be seen as a monster. This horrific creature was easily taller than Shouji, its large, thin yet muscular form was accompanied by its large head and tan armored skin covering darker visible muscle. Beneath its skin was glowing orange, as if a hidden power was hiding just beneath its flesh.
"Where is All Might...?" The man with hands asked. "We got a special summon from the depths of Hell and I want to see what he's capable of." Suddenly another portal opened in front of the students, Aizawa and Thirteen preparing for a major battle whilst the students behind them prepared for the same. Out of the portal walked a hulking figure, his height and body akin to a slightly smaller All Might. His body was armored with the main color being green, accented with black on the left arm, boots, and crotch areas. His left pauldron was a matte bronze trailing down to the gauntlet, and both of his biceps were open. The abdominal area was orange along with the area between his right shoulder pad and his neck, and his helmet was simple and round, an internal light revealing rage-filled eyes. The main items the students focused on were the man's launcher sitting atop his left shoulder, as well as the sheathed blade resting on the forearm of that same side.
"Of all the places the portal could have led to, I did not expect to end up in Japan." Hayden's voice rung in the Slayer's helmet, the man pulling out his Super Shotgun at the sight of the demons. The blades of the meathook widened, ready to sink into the flesh of the demons ahead.
"H-Hey, what's this?! Don't tell me you pulled a random five star!" Shigaraki Tomura said, as the Archvile beside him took a step back. "I pulled a ritual for you, you overgrown level one fodder! Don't go being scared now!" The demon turned to the villain leader, as an unholy voice rang from its mouth.
"You did not warn us that he was here..." The demon growled out, staring down the Slayer. He pulled down the barrels of the weapon, loading two shells in one hand and flicking the gun upwards to close it, the hook glowing beneath the barrels.
"Oi, who the fuck are you?!" Bakugou yelled, the man turning around. In the illuminated eyes of his helmet, Bakugou could see recognition, quickly replaced by rage once more towards the monster next to the villains. The Slayer looked to the farthest right side of his hud, the message Now Playing: The Only Thing They Fear Is You appearing in that corner before disappearing.
"It doesn't matter who he is! Destroy him!" The demon roared in acknowledgement, as the Slayer motioned for the teachers and students of UA to back away.
With the Archvile's roar came dozens of flaming shapes, each one spawning more creatures of various shapes and sizes. From the fast but scrawny Imps to the flying Cacodemons, all of these newly summoned demons were stronger and faster as a result of the Archvile’s magic, each and every one focusing on one specific target.
"KILL THE SLAYER!!!" The leading demon roared, as the destroyer of the Icon of Sin fired his meathook. The flaming chain latched onto the closest imp, pulling the Slayer towards it to unload both shells into the demon, obliterating it.
As the guts and gore flew away the armored man turned to a group of imps and gargoyles, firing an ice grenade from his shoulder cannon at them. Upon contact it froze the group as the man followed it up with the flamethrower beneath the launcher, setting the frozen demons on fire as he finished them off with two blasts of the Super Shotgun. The man switched to his combat shotgun, attaching the grenade launcher to fire one into the mouth of an incoming Cacodemon. It swallowed the grenade and faltered, giving the man the opportunity to run towards it and rip out its eye in a shower of blue blood.
RIP AND TEAR. RIP AND TEAR. RIP AND TEAR. rang through the Slayer's helmet as the song within continued to blast into his ears. RIP AND TEAR. The Slayer obliged, continuing his onslaught with his chainsaw running through another imp. The USJ looked like a bloodbath now, the blood of the demons splattering across the main area of the building.
The Slayer fired a shotgun blast at a soldier that attempted to shoot him from behind, hooking its left arm into his right as he stabbed through the chest twice with his Doomblade, and once more through the right eye to make sure it was dead. The body was thrown away as he switched to his heavy assault cannon, quickly attaching the scope as he jumped into the air. Chrono Strike activated, slowing down the Slayer's perspective of time as he used the chance to fire an enhanced round into the cannon of a Revenant, the shrapnel from the explosion embedding into its implants and skull. Instead of focusing it he whipped out his chainsaw to shower the floor in another Gargoyle's guts, restocking on ammo before aiming towards the other cannon. Before he could hit it the Revenant fired a rocket barrage at him with its remaining cannon, the Slayer dashing to the left to throw off the tracking of the rockets before destroying the other cannon with a shotgun grenade. He charged the stunned demon, slugging it with a hard left hook, followed by a right as he then grabbed its head with both hands and brought it down on his rising knee hard enough to cave in the skull. He was now soaked in demon blood, his helmet showing the rage-filled glee in his eyes.
As the Slayer was busy with yet another slaughter of demons, the students could only watch with a mixture of fascination and horror at the scene in front of them.
"He's a murderer..." Ojiro said, watching him snap a Prowler's arm like a twig, stabbing the now exposed bone through its mouth and out the other side of the head.
"All of his moves are effective, each one made to ensure that his target is dispatched in the quickest, yet most brutal way possible." Momo commented, stomach lurching as she watched him slam his fist into a zombie's head, caving it into the creature's torso as a stupefied expression was left on its face.
"SCARY!!!" Mineta screamed. All the others could do was try not to hurl while staying as far away from the carnage as possible. Thirteen and Aizawa remained in front of them as a last line of defense, Black Hole ready for any invading creatures while Aizawa stepped forward.
"No matter this stranger's brutal methods, we cannot assume he is an ally. Iida, get out of here and alarm UA of the situation." Aizawa said, as Iida turned to him.
"Sir, I can't just leave you-" "You're the fastest out of all of us. If you can get back and warn the school of this attack then we can avoid any unwarranted casualties." Aizawa then watched the Slayer grab a Prowler from behind, ripping out its spine with the head still attached. "Any more casualties." Iida was about to move when the black mist villain appeared behind them.
"Forgive me heroes, but we cannot let you get away that easily. While that man is distracted I am under orders to make sure that none of you shall leave." Thirteen would have activated Black Hole, but too many students were in the way for them to activate it safely. Kurogiri was about to open a portal to warp them across the separate zones where more demons were waiting. Before he could warp the students he had to warp out of the way as a sniper shot cracked through the door where his metal weakness just was. The class turned back to the Slayer, holding his assault cannon towards where the villain was, bringing his foot down onto the skull of a zombie, splattering chunks of bone and grey matter across the surface of the floor as he continued the carnage. Iida took the opportunity the mysterious man gave him to slam open the gates to the USJ, escaping as villains came in through Kurogiri’s portal to join the demonic forces.
"While he's fightin' we can get the kids!" One villain screamed, the rest charging in with them.
"Thirteen, get to UA with the students. I'll hold off the villains!" Aizawa said, dropping his goggles down over his eyes. He jumped into the air, latching his capture weapon onto a nearby mutant-type villain, flying into him with a dropkick as the Slayer followed this by firing a volley of rockets at the Archvile that led them. Whenever a demon tried to pounce on Aizawa the Slayer either shot it to pieces or flew towards it with a flaming hook, and tanked any bullets or blows that Aizawa could not thanks to the power of his suit.
"We should listen to Eraserhead's advice while we can and get out of here!" Thirteen said, the other nodding to move in after him. Kurogiri blocked their way again, as the Slayer was busy trailing the Archvile and Aizawa was still battling the villains.
"Not this time!" Sero yelled, seeing a flash of metal within the growing cloud of smoke. He shot a strand of tape at the villain, backing up afterwards as Thirteen activated Black Hole to stop him. The villain retaliated by opening a portal, the other point being behind the Slayer as an attempt to take him out, but the man threw a gargoyle in the way as he flew towards a Hell Knight with his hook. Bakugou and Kirishima rushed the villain to distract him, giving Tooru the chance to sneak behind him with Sero and Sato to pin down the villain. Meanwhile, Aizawa was focusing on the battle ahead, but with also the mysterious figure that was helping them.
'He appears to only be focusing on the monsters, leaving me to take on the villains.' Aizawa noted, swinging in circles around a mutant-type villain to deliver another flying kick towards his face, knocking him out. He tried knocking out a soldier demon by slamming its head into the ground, but it got up and began to shoot at him, killing one of the human villains who was in the way. 'The monsters don't seem to care about what damage they do to each other.' Aizawa saw a few demons the Slayer left as he went to take care of other ones, which had chunks of flesh missing from their bodies, some of their limbs showing the bone underneath. 'And their injuries don't appear to hinder them when even a tenth of that damage would make a normal person pass out or die from blood loss.' He saw more of these monsters start coming from the other zones, most likely what would have been the fate of the students had the armored man not appeared.
He pulled himself out of the way of incoming fire, turning to see the Archvile from before. It too was missing pieces of its body, but unlike regular flesh and bone the gore it possessed was bright orange, as if it were made entirely of magma beneath the skin. It put up a protective wall as it attacked Aizawa, shooting even more fire as the underground hero desperately swung out of the way. The demon jumped towards him, leaving a massive shockwave that reduced a few demons in the blast radius to paste.
"Why... are... none of the hero scum DYING?!" Shigaraki yelled, witnessing the lack of student and teacher death in favor of all of his summons dying. That Slayer the Archvile was screeching about turned out to be a much bigger problem than he thought, taking out the demons he thought would tear them apart with ease, like a player revisiting the first level after beating the game. Kurogiri appeared afterwards, delivering a message.
"I went to warp away the students, however that armored man interrupted me with a gunshot that almost hit my vital area. As a result they were able to escape. I sent in reinforcements as well, but it seems that Eraserhead is taking care of them."
"Kurogiri... If you weren't our ticket out of here, then I would have disintegrated you. It doesn't matter. Send in the backup plan." Kurogiri activated his quirk again, a hulking monstrosity walking out of the portal. Unlike the demons, this one had a beak for a mouth as well as an exposed brain, its flesh being midnight black and extremely muscular rather than the thinner body structure of the Archvile demon. "Nomu, take care of the Slayer."
The Slayer was currently dealing with the last of the demons, slicing off the Archvile's head with his blade, sheathing it only to be immediately tackled by a flash of black. When he looked up, he glared into the face of the Nomu before immediately firing his Super Shotgun, discovering that he was currently out of shells.
"This thing was meant to kill All Might! Even if you could get out of there alive, don't think you'd survive any longer than that!" The Nomu raised a heavy fist to crush the armored man, the Slayer catching the fist just before it crashed down onto him with a grunt. As he caught the fist the floor around him broke under his feet, spiderweb cracks spreading outwards as he was pinned from keeping the attack at bay. Aizawa wrapped his capture weapon around the arm to try and help the man but the Nomu simply jerked its pulled back arm to the side to send Aizawa flying. He crashed into a wall, the Nomu using the capture weapon to then fling the attached Aizawa into the ground, bouncing painfully off of the floor. The Slayer took this moment of distraction to switch to the Ballista, placing the barrel of the massive weapon at the beast's diaphragm. Having the Destroyer Blade mod active allowed him to fire a massive horizontal energy blade that split the creature in half.
The Slayer used the time he gained to switch back to the assault cannon again. He replaced the scope with two modules on each side, opening them to reveal lines of missiles when he saw the Nomu regrow its upper body. He wasted no time unloading on it, taking into consideration Shigaraki's taunts about it having regeneration and shock absorption.
Aizawa got up next to the armored man, staring down the monster from behind his goggles.
"I don't condone your method of dealing with those creatures, but I do acknowledge that lethal force was necessary to protect Thirteen and the other students, so thank you for that. Hopefully they made contact with UA. In the meantime, let me assist you in defeating this creature." The slayer nodded, and the two charged the monster in front of them.
"Not so fast heroes! I just so happen to have a perfect buff for this!" Out of Kurogiri Shigaraki pulled out a waist-high black pillar, a green orb at the top beneath a winged skull. The Slayer's eyes widened as a fist suddenly sent him flying, the Nomu even stronger and faster than before. The armored man caught the next punch with both hands, letting go for it to fly past his head as he delivered a blow of his own. Blood Punch activated, the impact creating a massive shockwave. However, the Buff Totem amplified the Nomu's Quirks, allowing it to take the blow like it was nothing. The Slayer did it again, the Shock absorption temporarily becoming shock nullification. The Nomu then slammed a volley of punches into the man's armored body, each punch similar to a Pinky charge as each landed blow hit hard. He caught the incoming left fist with both arms, cutting off the hand with the Doomblade and dashed away as the hand regrew.
As he was planning a way to deal with the creature, Aizawa was trying to think of a way to help. He saw the villain put down the totem earlier, and knew that this was his main target for now.
The Slayer cut off the beast's arm and backed up again, the Nomu immediately growing another one to carry the pressure on. The monster descended onto the man, who pried open its mouth from below it to fire a frag grenade inside while the weight on him started to crack the ground beneath his feet. He rolled out of the way of an earth-shattering fist and countered the attack with an ice grenade, temporarily freezing the creature in place while the grenade inside clustered and exploded, damaging it within the ice. While this was happening Aizawa was currently struggling against Shigaraki, dodging palm swipes as he tried to go for the Totem.
"Nomu!" Shigaraki yelled, and suddenly Aizawa was in a world of pain as the boosted creature rammed into him with its shoulder. As he flew through the air the Nomu grabbed him with bone-shattering strength, and Aizawa could swear he could feel each of his bones cracking as he was caught in the monster's grip. He then tried using his Quirk on the creature to give himself some advantage, but it did nothing to him, much to Shigaraki's glee. The Nomu then slammed him into the floor, forming a crater upon impact as it raised its fist. Before the lethal punch could be thrown, the arm fell to the floor with the sound of hissing coming from behind it. Shigaraki looked to see the Slayer wielding the Crucible Blade, looking towards Aizawa and nodding. The teacher threw out his capture weapon with as much force as he could still muster, the Slayer catching it and pulling him away from the Nomu and towards Shigaraki. The blue-haired man anticipated that his Quirk would be erased so he looked to Kurogiri to redirect the incoming man towards a farther away zone, but was shocked when Kurogiri's portal would not open. In that moment of shock Aizawa was able to slam a foot through the green orb of the totem, shattering it and flying past both of them despite Shigaraki's incoming attack.
Since the Nomu was missing an arm and was no longer boosted by the totem, the Slayer was able to take the chance to finish it off. It threw a volley of punches with its remaining arm, the Slayer catching the fist with the spikes on his right gauntlet. He brought down a foot on the creature's left leg, bending it backwards with a small spray of blood and splintered bone. He then removed the impaled fist from his gauntlet by slicing it off at the wrist with the Crucible, carbonizing the stump and preventing it from regenerating again. The screeching of pain was ignored as the monster was kicked onto its back, leg slowly repairing itself not fast enough as the Slayer brought down the blade, dividing the creature in two vertically. He placed the deactivated hilt back on his belt whilst Shigaraki was left to stare in shock.
"H...How the hell did you do that?! What cheats did you use to kill my buffed Nomu?!" Shigaraki charged the Slayer to try and take him out, but a quick shot from behind the Slayer pierced his hand.
"SENSEI!!!" Iida's voice rang, causing both of them to turn around as more bullets stopped the man from running away. "CLASS 1-A HAS ARRIVED WITH REINFORCEMENTS!!!!" Next to Iida was All Might, accompanied by a collection of pro heroes and the rest of 1-A, still incredibly fearful of the armored man.
"Next time... you won't be so lucky!" Shigaraki said, a portal sending him and Kurogiri away after his other hand and his legs were pierced by three more bullets.
Aizawa limped his way back to the Slayer, who looked at the man with a look of concern in his eyes.
"I'll be fine. That creature might have broken a few bones but other than that I'm fine." In truth Aizawa looked and felt like he just got hit by a truck at full speed, but with Recovery Girl there he would be alright. The Slayer nodded and was about to walk away, until he realized that a hero in cowboy attire was now pointing his gun at him.
"Now, tell me why you are here, and why there is a creature's corpse and blood everywhere." All Might said, a scowl on his normally smiling face. His fists clenched, and in response the Slayer pumped his shotgun, the only sound in the room being the spent shell clattering along the floor.
"Now, now, let us all calm down before a fight begins." Nezu said, standing on All Might's shoulder. He hopped down, and despite the heroes currently warning him against it he walked up towards the Slayer calmly. "No student or teacher appears to have been harmed aside from Aizawa, and that was because he stayed behind to help protect the students. Is that correct?" Nezu looked to the armored man, and Samuel Hayden's voice spoke for him.
"That was what had happened. Demons appeared alongside a man with hands over his body and a man made of black smoke shortly before we arrived."
"Demons, you say?"
"You tell me that this world does not know of the demons?"
"It appears so, as this is the first time I've heard of them. Would you mind giving us a name to work with?"
"That is very interesting to know. My name is Samuel Hayden, former Chairman of the U.A.C., and after that the leader of the ARC Resistance to combat the demonic invasion of Earth." The Slayer then reached for his helmet, pulling it off of his head to make Bakugou's eyes widen from the background.
"And the man I traveled with is known as the Doom Slayer, savior of Argent D'Nur, and the only man the demons fear." When the helmet lifted, emerald green eyes stared back as green hair fell into place. "Although, ancient Argenta scripture recalls that his name is Midoriya Izuku."
"Deku...?"