You know where this is going by now.

After he'd slain the Spider Mastermind, Doomguy was betrayed by Dr. Samuel Hayden. The Crucible was taken from him, and the doctor had believed he'd sent Doomguy back to Hell. Instead, Doomguy has been sent to the world of Remnant. Now, stripped of his power, Doomguy must accustom himself to life on Remnant, while also contending with life with four new, quirky allies. I do not own any of the characters in this story. Respective rights go to Rooster Teeth for RWBY and Bethesda Softworks & id Software for DOOM. Enjoy!

You the Doom Slayer, had just gotten back to Mars after going to Hell and retrieving the Crucible. Hayden freezes you and takes the Crucible before teleporting you to some place unknown. Well what if you were sent to a different universe?

A DOOM X GATE: Thus the JSDF Fought There Tale.

This occurs after the third volume. Everyone though that Pyrrha died in the battle of Beacon. Though now she has been taken to a whole new different world and now has to fight creatures that she never seen before. Though these creatures are more dangerous than any Grimm she has encountered. Now she has fight her way out of Mars and Hell literally and joins forces with the one man that hell itself fears. They call him the Doom Slayer and will she be able to get back home. Will the Doom Slayer be able to recover what he though he lost after his home and the people he cared about were taken away by hell his humanity. (I got this idea from playing Doom 2016 and it's a awesome game. Also taking a different way of telling the is story since there aren't a lot of Doom and RWBY story and none appear in that world.)

the Doom slayer has defeated the mastermind and the forces of hell. samuel Hayden has sent the slayer away from the mars facility to a new world. one where not everything is trying to kill him. I do not own Doom or RWBY they belong to their respective owners.