Authors Note: This is a rather simple story I was inspired to make by something similar in the Naruto story Win Some, Lose Some (Which I highly recommend) by obsidian dreamer. I had been wanting to do a RWBY x DOOM story for a while but could never quite figure out how I wanted to do it until I ended up writing this. I would have posted it sooner but was unsure if I wanted to continue it or how. If I do decide to continue this it won't be for a while, so I recommend not getting your hopes up if you like this.

That said, enjoy the story.

It was Hell.

There was no other way to put it. Vale had been turned into a hellscape in the span of only three hours. Everything had been perfectly fine just hours before. The Vytal Festival was nearly over and there were only the single matches left. Then it was revealed that one of the competitors was a robot when she was accidentally killed by Pyrrha Nikos in their battle. Then the announcement came. Some woman going on about using kids to fight a war and trying to rile the people up.

It worked.

Grimm flooded the city and the White Fang air dropped cages full of them directly into the city, school, and stadium. The students did their best to hold off the Grimm they could and get people to safety, holding on to the designated safe zones for as long as possible. Killing wave after wave of Grimm with no end in sight. No one had seen Ozpin in nearly an hour and command was as scattered as the people of Vale. The streets were shredded, flowing with the blood of people who couldn't get out in time. Atlas' military bots had been taken over, but had just stopped half an hour ago. It was a win that had been greatly overwritten by the appearance of the Grimm Wyvern.

Suffice to say Cinder Fall had taken great pleasure in her victory. All that was left to do was to take care of the false hope that now kneel before her. It wouldn't be long before she succumb to the fire dust flowing in her veins, and while that could be fun, Cinder knew the dangers of playing with her food all too well. So as she walked up to defeated form of Pyrrha Nikos the mere inkling that things could turn around on her were left far, far behind.

Just before she could make contact with her victim, showing the world what she was made of, two figures shot up into the clockwork and glass office. The first was a familiar face, a girl clad in red holding a weapon nearly double her size. Young Ruby Rose staring hard at the treacherous Cinder Fall. The other, though, no one knew. Attention was drawn to him as he landed in the office only a second later. He was a tall man, standing at least six foot four inches clad in thick green armor and holding a double barreled shotgun.

The women all stared at him in confusion and curiosity. He seemed to examine them all for a second before turning away from them and pulling out an insanely large green gun. He then had the audacity, guts, balls, to extend a blade from his left forearm and stab the Grimm Dragon in the eye. The women all stared in shock as the creature roared in pain and thrashed around, shaking the tower dangerously before it turned to the mortal that dared do it harm.

The massive Grimm turned to face its assailant, thoughts of its masters chosen being in the tower wiped from its head as it readied its jaws to snap at this foolish mortal. It snapped its jaws forward to attack, but it didn't make it very far. From the second the Wyvern had turned to face its assailant, the gun it was holding had been charging. The second its jaws were open, the gun was ready. As soon as it snapped forward, the gun was fired.

The beast never stood a chance.

The Wyvern stopped in place as a green ball of pure plasma the size of a beach ball entered its mouth. All the beast knew was burning pain as bolts of green lighting shot from the ball, melting it from the inside. After a few seconds, the ball exploded, sending chunks of Wyvern flying into the air and down to the ground, rocking the tower in the process.

The room was silent.

The world was silent.

No one who had witnessed this action could believe it had actually happened. It was too… it was just impossible. There was just no way that such a feat could be accomplished with a single pull of a trigger.

Cinders confusion gave into fear gave into anger. How could one person destroy such an ancient and powerful creature in a single blast? How dare they make her feel fear?! She was better than that, dammit! She wasn't afraid of anyone but Salem, and even then that fear was well founded. This wasn't. This was some random person with a gun! This wasn't possible!

"How dare you?!" She shouted, all attention turned to the green intruder. "How dare you destroy my dragon?! How dare you ruin my plans?!" She shouted, fire erupting from her hands.

Before she even got a chance to throw out a fire ball the figure was facing her with a different but still very large weapon. This one was white with a blue energy coming from the barrel. She never knew what hit her. The second the barrel was pointed at her it fired a beam of blue light. It took her almost six seconds to realize it shot right through her left shoulder. She screamed. It was piercing and shrill, but the figure paid no attention as he stepped towards her, his steps heavy and menacing.

"Get away from me!" Cinder shouted, backing away as the fear overtook her. That weapon had pierced straight through her aura like it wasn't even there. She hated this feeling, but she gave into her instincts, choosing to live instead of face this monster. She used her good arm and threw a fireball at him. He stepped through the attack like it wasn't even there. Then another. Then another.

The figure towered over her, its blank mask imposing and speaking only of her doom. It wasn't until he was in arms distance did she think to try to fly away. She made it all of seven feet into the air before he grabbed her ankle and slammed her into the glass floor, cracking it. Before she could recover she felt his heavy boot slam into her gut, causing her to cough up blood and cracking the glass beneath her further. One more attack like that and she just may be able to escape when she falls. Unfortunately, the person in front of her was smarter than that. She let out a terrified whine as she felt the cold metal of the suit wrap around her neck tightly.

"Let me go!" She gasped as the hand squeezed, holding her off her feet. She struggled worthlessly in the air, kicking and scratching and flailing as the hand only wrapped tighter and tighter around her throat, making it harder and harder to do anything. In a last ditch effort to escape she lit herself on fire, hoping it would cause the figure to let her go. The fire died after five seconds. It had done nothing to stop the hand and she was barely keeping consciousness at this point.

Cinder knew she must look pathetic. She could feel the hot tears running down her face. Gods, her mascara must be running terribly. She could see herself in her oxygen deprived delirium. Puffy red eyes flowing with tears, silently pleading for mercy where she knew there would be none. She hated herself. She promised she would never feel like this again. This helpless. She wanted the power to do this to others. It was what everything was for! It was why she wasted her time at Beacon pretending to be friends with those naive children! And this was how she died. At the hands of some faceless bastard who showed up just in time to ruin her plans. Three years of planning down the drain. She would curse whoever this was. She'd haunt them if she could. And in her final moment she heard the figure speak, a gruff and cracked voice that didn't seem to be used often.

"Enjoy your time in Hell." The man said.

A loud snap cut through the silence of the room, causing Ruby to gasp at the brutality. No one who was watching the broadcast knew what to think of the green clad figure holding the now limp body of the woman who had caused so much death and despair. Most cheered, others were still in shock. The Man tossed the body aside callously, letting it rag doll on the cold glass floor before turning to face the two red heads.

He stepped towards Pyrrha, who wanted to crawl away but was too injured to move. Ruby started to block his path, but he stopped a few steps away from the downed warrior and kneeled. There was a click as he moved his hands to remove his helmet. Short blond hair shown first, followed by a pair of familiar blue eyes.

"Jaune." Both girls gasped.

"It's been a long time, Pyr." He smiled at her.