DOOM: Equestria

by Harsh productions

Rating: teen
Tags: Twilight Sparkle, Princess Luna, Gore, My Little Pony: Friendship is Magic, Princess Cadance, Alternate Universe, Thriller, Adventure, Violence, Princess Celestia, Crossover, Death
Length: 3828

The demon apocalypse has invaded Equestria. Now The Slayer must fulfill his holy duty and rid yet another world from the demonic affliction.

Samual Hayden did not trust the Doom slayer to agree with his plan of using demon energy to rid earth of the demons. So he preemptively sent The Slayer far away, so that he wouldn’t interfere and destroy the artifact before he could use the evil power for good.

Now The Slayer is stranded in the far reaches of the universe. Determined to make it back to earth and end the demon apocalypse the only way he knows how. But the planet he has found himself stranded on has been overrun with demons, and now he must fight. He will not let another innocent world fall to the demons. Equestria will persevere, and he will rip and tear until it is done.

thumbnail art made by me.

Published 2025-02-10 06:40:01 UTC
Last updated 2025-02-10 06:40:01 UTC

The only thing they fear

The once clear blue skies of Equestria have now turned red with hate, and the air has been tainted by the by the smoke and fire that has erupted from the pits of hell. The laughter of filly’s and colts on their way to school have been replaced with the roars and screams of the damned, and the once luscious green grass has now been stained red with the blood and guts of the innocent. The peaceful nature of Equestria had been forever corrupted by a demonic infestation that spread far and fast across this land. They don’t know where they came from, but all they know is that it started in ponyville, a place so heavily infested that not a single soul dares to enter. Equestria wasn’t ready for war, and it fell to the demons faster than they anticipated. The Equestrian army fell to their knees as they were overrun, and the saviors known as the elements of harmony died in vain trying to protect the Equestrian citizens. Eventually, Equestria ran out of resources to continue fighting the onslaught of demons and all they could do was run and hide.

The demons never stopped coming, no matter how many of them were killed. They didn’t fear death. They climbed over their fellow demons' corpses in order to kill as many of the ponies as they could. They were heartless creatures of pure evil that wanted to do nothing but inflict suffering on those around them. As of now, there is nopony left to fight. The only three ponies that could stand a chance against the horde were cowering in fear from the forces of hell and bunkering themselves up in the throne room of the castle of Equestria’s capital city of Canterlot. The three remaining ponies were Alicorn princesses. The Princess of Friendship, Love, and The Moon were all that was left. The Princess of the sun was currently missing, and she has been missing ever since the distress signal she made that now plays on repeat to anyone that can hear it, in a desperate plea for aid.

The only thing standing between them and the horde of demons outside was a door with a marking carved into it. It seemed to be the one and only thing the forces of hell genuinely feared. Its meaning is unknown to the ponies, but the demons seem to fear whatever it represents. They fear the mark so much that they refuse to even touch objects that had it carved into it. Because of this deep-rooted fear they have for this marking, some ponies have attempted to don the mark on their armor in a desperate attempt to ward them off, but these efforts were in vain, for they were torn apart like all the rest.

There was only one being alive that wore that symbol and truly struck fear into the demons. He was the beast the mark represented. He was not a pony, nor was he a demon. There’s even debate on whether or not he’s even human. All that is know is that he wears a dark green suit of praetor armor that covers his entire body and is armed to the teeth with firepower. The praetor suit made him practically invincible, and he possesses such immense strength that his might is equivalent to that of a god, and just like a god he is countless centuries old.

For eons he fought the forces of hell, with boiling blood and ravenous hatred, he scoured the umbrel planes, seeking vengeance from the dark lords who had wronged him. But as he cut through the horde and slaughtered beasts larger than him, he found no peace. But he continued his relentless and ceaseless devotion to the extermination of all demon kind, his unfathomable hatred for them fueled his rampage as he inflicting endless suffering upon them for countless generations, and striking fear into hell itself. They eventually were able to restrain the beast with great effort and sealed him away. They marked the casket he was trapped in with a symbol that warned the other demon of what was housed inside, and that it must never be set free.

Eons later, the UAC of earth set up an energy and research facility on mars, harnessing hells power and repurposing it into clean argent energy and collecting demonic artifacts to study the foreign dimensions history. In their quest for knowledge, they uncovered the very coffin that housed the beast the demons were only lucky to capture, along with the history attached to it. Olivia Pierce, a head researcher on the argent facility on mars, made a pact with a dark lord of hell and aided them in their eventual invasion of mars. The promise of power so great it could transform Olivia into a god and cure her chronic pain from her implants was something she couldn’t pass up. Once the demons began their invasion, Samual Hayden, her mentor, released the man locked away in the sarcophagus to combat the demons. He did just that, destroying the argent energy and every single demon that got in his way. HE used a demon crucible to aid him in stopping the demonic invasion, stopping the invasion from the other side. But once he returned to the facility, Samual Hayden took the crucible from him, wanting to use it to combat the demons.

Samual knew the man he used to ward of the invasion wouldn’t understand his desire to use demonic energy to destroy the demons, especially since he destroyed the argent energy. So he sent him far away from earth so that he couldn’t get in his way. Now he reemerges in Equestria, left stranded in an unknown world that just so happened to be ravaged by the forces of doom. So, he stepped into action and continued down the path of perpetual torment he had chosen long ago. All in an effort to get back to earth in any way possible.

The name this bane of hell once possessed has been lost to time, but the ones who have tasted the bite of his sword now only know him by one name…

The Doom Slayer.

Author's Note

Throughout the rest of the story, you will see text with links attached to them. They will lead you to music from this franchise, think of it as soundtracks for the "level" they're on. They also helped me envision the battles that they will inevitably depict. Enjoy.

A sickle through a field

The city of Filly-delphia has been overrun, the streets are now filled with demons of various types as they hunted for the last surviving members of the Equestrian populous. The surrounding high-rise buildings have crumbled to the ground or had giant tentacles piercing through them. Many buildings had large portions broken off and suspended in the air by unknown means. Large chasms have opened up around the city, hellfire spewing forth from the mile wide crevices and further scaring the city. Various demonic symbols were carved into the sides of building all across the city. Some small pentagrams were painted in the blood of the innocent, while others were carved with fire on the side of high-rise buildings. Lava flowed from the building and ruble littered the city streets along with the demons that patrolled them. The skies were now unsafe for any remaining Pegasi to fly in as gargoyles, lost souls, and cacodemons dominated the airspace now. The broken bodies of the ponies were now strung up in the street, the skin and muscles peeled from their bones, and those very bones were so mangled that they were nearly unrecognizable. Those were probably the most intact corpses on the streets however, as the majority of the demon’s victims have been reduced to piles of charred meat on the ground. The ponies couldn’t escape the demons, they were too fast. The few remaining ponies that were left have lost all hope in any kind of savor coming for them.

But now, the fear the ponies had have seemingly transferred from the ponies to the demons, because the bane of hell has arrived. The Doom Slayer has finally emerged on the battlefield, and these demons will soon feel his wrath. The demon felt his presence, he had an aura about him that was powerful enough to strike fear into them by simply existing in their presence. Even demons on the other side of Filly-delphia were stricken with fear as he stood atop a pile of rubble high above the ruined city. He looked down at the broken street in disgust as the forces of hell now tried to climb up the rubble to get to him. They may be scared of him, but that doesn’t mean they won’t go out without a fight.

But The Doom Slayer could fight harder and faster than them. He reached down in front of him, a small portal opening up right in front of his hand. He reached inside this portal and pulled out his standard shotgun and waited for the imps to get to his level. Three imps quickly reached The Doom Slayers and roared at him, and The Slayers shotgun roared back. The blast tore through the center imp, sending chunks of meat raining back down to the street below. The second imp to the left suffered the same fate, and he then punched the last one across the face hard enough to stagger and daze it. He then swept that imps' feet out from underneath it; he then grabbed the imps face as it was still suspended in midair and brought it down to the ground hard, shattering its skull against the ground like glass. The slayer then sprinted off the high ground he had and plummeted down until he grabbed ahold of a cacodemon on his way down. he plunged his fist deep into his eye, causing the demon to screech in pain, and before the cacodemon imploded from the pain, the slayer jumped off the demon and bashed through a window of the dilapidated building he had just jumped off of earlier. More demons awaited him on this floor, but the quickly fell to his might. But the slayer was taken aback for a moment because of the sight of a few demons though, they looked like small horses, but they were clearly possessed by the demonic energy that had enveloped this land. The sight of these peculiar demons gave the slayer the clear indication that he was now nowhere near earth. Hayden had made sure he was far away from him, like he promised.

The slayer quicky resumed his train of thought and continued his slaughter; stomping on these possessed ponies Sholder blades until his boot made contact with the floor beneath, swiftly ending the life of these ponies as their body parts scattered across the floor. The slayer knew that before he made his way back to earth, he had to rid this world of the demons first. While he was determined to get back to earth and finish what Olivia pierce had stated, it could wait while he focused on cleansing this new world of its own invasion. He looked outside and into the distance of this new land he found himself in, out there he saw a castle way off in the distance connected to a mountain's cliffside.

"That castle is emanating a distress call." Vega said from within the slayers armor. "I will attempt to patch into this signal. But in my limited state, I make no promises."

The slayer understood that a hyper advanced AI was ill equipped to function at full capacity with his suit's hardware, but radio communications should be light work so it shouldn't take too long for Vega to access this broadcast. but in the meantime, he was going to dispatch more forces of hell until there was nothing left to come after him. he scaled down the ruins of the city, dispatching every last demon that dared to find itself captured by the slayers gaze. He hunted the slaves of doom with barbaric cruelty until he reached street level. more Imps and possessed ponies fell to his unyielding might, but a hell knight decided to take its changes against the hellwalker himself. It leaped into the air, aiming to land on the slayer and end his rampage. but the slayer was much faster than the hell knight and had already made it behind the demon before he hit the ground. he then pulled out his heavy assault rifle and began riddling the demon with bullets. The hell knight attempted to close the distance between him and the slayer, but the slayer made it so that he was always just out of reach as he strafed to the side and as he pumped the demon full of lead. Soon enough the hell knight was brought to its knees, and the slayer quickly closed the distance and shoved the hell knights head to the ground and smushed it underneath the weight of his boot like a watermelon.

"I have accessed the distress signal for you." Vega said before playing the message in question.

"My name is princess Celestia, princess of the sun, and ruler of Equestria. My sister princess Luna, my faithful student princess Twilight Sparkle, and my adopted niece princess Mi Amore Cadenza are all that is left after the demonic invaders attacked our land suddenly and forcefully. We don't know where they came from and what they want from us, but it seems the only thing they desire is our deaths. We have exhausted all of our resources to try and hold them back, but they won't stop advancing. Our magic had already been weakening prior to the invasion by unknown means for the last few days, and on the day a trusted friend predicted all magic to fade completely from Equestria... this happened. I don't know if these two events are related, but that doesn't matter anymore. I want these heartless monsters out of my land, but we are far too weak to put up any meaningful fight. I've failed to keep Equestria safe, and I'm at a loss for what to do next. This message is for any creature that may hear it. If you have the ability to help drive this army back, please lend us your aid in either military might, or in helping us escape from the castle in Canterlot. We are holed up in the throne room for the time being, a temporary solution has been found to keep them at bay, but it won't last forever. please... we need to find a way to fix this... to rebuild what we've lost. This can't be the end for Equestria. "

"This message has been on loops for a few days now. I suggest finding a way to Canterlot, perhaps these princesses are still alive." Vega said. "I spotted a train station at the edge of the city when we were at the top of the building earlier. go to it, we will figure out our next course of action from there."

The slayer obeyed the AI's suggestion and cut through the horde as he made his way to the train station. Hell razers, imps, and zombie ponies were slaughtered by the slayer as he charged through the ruined city. The slayer eventually made it to the front of the train station, where many demons waited for the slayer. He readied himself for combat and dodged and weaved out of the way of an imps' fireballs and closed the distance and pushed it to the ground, before stomping on his skull, crushing it with ease. He then hopped down to a lower level, into what was essentially an arena, and landed on top of a hell razer and placing the muzzle of the shotgun to the back of its head and blasting its skull apart. he then aimed up from the ground and toward a few advancing imps, with a simple flex of the trigger the shotgun tore through the imps, sending chunks of meat soaring in every direction. Before the slayer could close the distance on the other imps that escaped the first shotgun blast, he was punched by a hell knight. He went soaring across the arena but planted his feet firmly to the ground and stared down the hell knight as it charged towards the slayer. He pulled out his heavy assault rifle and began to fire it at the charging demon as he strafed backwards. Out of the corner of his eye, he saw a second hell knight quickly closing the distance. The slayer quickly strafed out of the way of both of the knights, threading the needle as he slipped through both of their grasps. They bashed into one another and heavily injured each other in their collision, but they quickly recovered, and both charged towards the slayer once more. The slayer saw both knights jump towards him, so he put imps in the way of the hell knights as he divided his attention to filling the other demons around the arena full of holes. The knights obliterated the imps upon impact and continued to charge towards the slayer like charging bulls in a desperate attempt to end his rampage. But one of the knights fell to his knees, groaning in pain from the bullet wounds that the slayer had riddled his body with. The slayer made his way behind this hell knight and baited the second hell knight to punch through it to get to him, the guts exploded out of the demon's corpse and caused the surviving hell knight to slip on the slick red guts. The remaining hell knight panicked as it tried to climb back onto his feet, but before he could fully recover the slayer took aim with his shotgun and reduced its head to pink mist.

The slayer took a quick look around him and saw that there were no demons left in the general vicinity to attack him, so he ventured forward through the city, scaling the ruins as he made his way closer to his destination. The train station was a large building with a now delipidated ceiling. the main doors where now inaccessible from the gore and rubble that now blocked it. So, he used the rubble to scale the building and looked down into the empty train station. The only thing inside the building were demons that aimlessly roamed around the floor. A load, distant and distorted roar of a steam train was heard rapidly approaching the train station, and it wasn't slowing down. If that train was heading towards that castle, then the slayer was getting on that train. He braced himself for impact and jumped off the roof of the train station and crashed through the roof of the train's boxcar.

He looked up and saw a fair number of imps, ponified mecha zombies, and hell razers that began to close the distance once they realized who their new occupant was. But closing the distance was a bad move from the demons, because the slayer grabbed the nearest hell razer and snapped his neck with a sickening crunch. He then grabbed the mecha zombies by the front hoofs and lifted it into the air and used its arm cannon to set the imps on fire, before turning the weapon around on zombie and forcing it to kill itself. The slayer then tore the sharpened mechanical hoof off and rammed it into the eye socked of the nearest imp, the improvised weapon poking out the back of the imp's skull before it collapsed to the ground. A hell razer hit the slayer on the back of the head, which did nothing but piss the slayer off. He then hooked the hell razers arm under his armpit and with a single, powerful punch he obliterated the armored skull of the hell razer. He then pulled out his shotgun and pumped the remaining imps full of lead. A single hell razer remained, and before it could charge up its laser the slayer reached into another small portal and pulled out a chainsaw and sunk the teeth of this mechanical beast into the shoulder of the demon and rocked it back and forth to work its way through the bones and slice it in half. blood and guts spraying across the room as the demons was chewed apart by the chainsaw, until the two chunks crumbled to the floor with a wet and meaty thud. the slayer put the chainsaw away as he verified the room was now clear.

The far door that leads to the rest of the boxcars was being pounded on by more cannon fodder. The slayer turned his back on this door for now as he went through the opposite door that led to the engine room. He then plugged Vega into the demonic console for a quick moment so he could download any information he could. He then plugged Vega back into his suit, and Vega informed him of the relevant information.

"Canterlot is two hours away. It is also this trains next stop. The demons on board might make this trip more difficult than it needs to be."

The slayer slammed his fist into his palm as he turned and walked over to the door the demons were pounding on. eventually they broke through, and as quickly as they entered the room, they were killed. The slayer never pulled out a gun to kill the oncoming hoard, he used his bare hand to rip and tear through the fodder. He grabbed an imp and threw it against the adjacent wall and crushed his head with his foot. He then grabbed another imp and split its skull in half with his bare hands, then driving his fist through the chest and out the back of another imp. A gargoyle then charged through the crowd in attempt to stab the slayer, but he grabbed the gargoyle's wrist and rammed its bladed hand back into the demon's skull and cleanly sliced it in half. He grabbed this corpse and discarded it behind him as he focused on dispatching the rest of the horde, his strength being so immense in this moment that he was capable of reducing demons to chunks in a single blow. he walked forward into the horde, punching and kicking every demon in his path, and it seemed that every demon he killed that another would take their place. But they would eventually stop coming, they would eventually all fall to the slayer. During a small break in the action the slayer peered down the remaining boxcars and saw that there were eight boxcars full of fodder crawling over one another to come after him. He was not fazed.

they will all fall to his might.