What are some interesting ideas for a Doom Slayer crossover fanfic?

Perhaps a crossover with a fantasy world. Doomguy enters a realm filled with magic, elves, and dragons. He might initially be seen as an outlander, but as he battles the demons that have also invaded this fantasy world, the inhabitants start to see him as a valuable ally. The clash between Doomguy's advanced weaponry and the magic of the fantasy world would be a fascinating aspect to write about.

For a Demon Slayer crossover fanfic, consider a crossover with Fairy Tail. The mages of Fairy Tail could use their magic to fight alongside the Demon Slayers. Natsu's fire magic would be really effective against some demons. Also, a crossover with Bleach would be fascinating. Soul Reapers could interact with the Demon Slayers, and they could exchange knowledge about dealing with spirits and demons. Ichigo's powerful sword skills could be a great addition to the fight against demons. And how about a crossover with Pokémon? Trainers could bring their Pokémon to the Demon Slayer world. A fire - type Pokémon like Charizard could be a powerful ally in battles against demons.

Some doom crossover fanfic ideas include a crossover with the Dark Souls universe. The Doom Slayer could be in the gloomy and challenging world of Dark Souls, facing off against tough bosses and hordes of undead. Another idea is a crossover with the Devil May Cry series. The Doom character might team up with Dante or Vergil to take on demonic threats. And a crossover with the Mass Effect universe could be about the Doom hero getting involved in the fight against the Reapers and other intergalactic menaces.

Another possibility is a crossover with the Mass Effect universe. The Doom Slayer arriving in the Milky Way and getting involved in the fight against the Reapers. His brute force approach might shock the more tactical Alliance forces, but it could also be the key to victory in some battles.

One idea could be a crossover with the Halo universe. Imagine the Doom Slayer facing off against the Covenant. Another could be a crossover with the Warhammer 40K universe, where the Doom Slayer battles Chaos forces in a hellish landscape that combines both universes. Or a crossover with the Mass Effect universe, where the Doom Slayer's brutal combat style clashes with the more strategic and technological approach of the Mass Effect races.

One interesting idea could be a doom fanfic where the protagonist is a new recruit in the Doom Slayer's army. They have to learn the ropes and face off against demons in a training scenario that goes horribly wrong, leading to an unexpected adventure. Another could be a fanfic set in a post - Doom world where the remaining humans are trying to rebuild and there are still hidden pockets of demonic activity that they have to deal with. And a third idea could be a fanfic that explores the backstory of one of the demons, perhaps giving it a more sympathetic angle before it became a monster in the Doom universe.

Definitely Geralt from The Witcher. His knowledge of monsters and magic could complement the Doom Slayer's brute force. They could work together to hunt down some powerful demons that are causing chaos in both their worlds.

One idea could be the Doom Slayer arriving in the RWBY world. He could be on a mission to stop some sort of demonic invasion that has seeped into Remnant. His powerful arsenal and unwavering determination would be a huge contrast to the Huntsmen and Huntresses of RWBY.

One idea could be a scenario where the Doom Slayer somehow ends up in the Halo universe. He might team up with the Master Chief to fight a common enemy that combines the demons from Doom and the Covenant or Flood from Halo. For example, a new threat that has the ability to corrupt both the technology in the Halo universe and summon Doom demons.

In a Doom and Wolfenstein crossover fanfiction, it could be that there is a portal that opens between the two worlds. The demons start pouring into the Wolfenstein world, and BJ has to reach out to the Doom Slayer for help. The Doom Slayer brings his arsenal of powerful weapons, and together they train the resistance fighters in Wolfenstein to use these weapons. They also discover that some of the Nazi technology can be modified to be more effective against the demons, creating a unique blend of combat strategies from both universes.