What are some interesting plot ideas for Warhammer 40K x Doom fanfiction?

A plot could involve the forces of Warhammer trying to harness the power of the Doom Slayer. They see his incredible combat abilities and want to use him in their battles. However, the Slayer has his own mission and is not easily swayed, leading to a conflict of interests and some intense battles.

One idea could be that the Doom Slayer is transported into the Warhammer universe. He might start by facing off against hordes of Orks in a brutal melee, using his signature weapons. His superhuman strength and unwavering determination would make him a force to be reckoned with among the various factions.

One idea could be a vampire Space Marine. Maybe a genetic experiment gone wrong in the Imperium that results in a Marine with vampiric traits. He has to struggle with his newfound thirst while still trying to fulfill his duty to the Emperor.

Another plot could revolve around a Rogue Trader facing a mutiny on their ship. Maybe the crew has been influenced by a chaos cult or they simply disagree with the Trader's latest high - risk venture. The Trader has to find a way to regain control and deal with the traitors.

One interesting idea could be the combination of Naruto's ninja abilities with the high - tech and grimdark elements of Warhammer 40k. For example, Naruto's shadow clone jutsu might be used in a unique way on the battlefields of the 41st millennium. Maybe the clones could be used to infiltrate enemy lines or to overwhelm ork mobs.

Perhaps a Dark Eldar wych could form an unlikely alliance with a Space Marine. Maybe the wych has a personal vendetta against a chaos warband that is also targeting the Space Marine's chapter, and they decide to work together to take down the common enemy. This would involve a lot of tense moments as they try to trust each other despite their very different cultures and motives.

Perhaps an Imperial Inquisitor ends up in the Star Wars galaxy and tries to manipulate the Sith and Jedi for his own ends. He could see the Sith as a useful tool, not realizing how dangerous they truly are until it's almost too late. This could lead to a three - way battle between the Inquisitor, the Sith, and the Jedi.

One idea could be a crossover with the Star Trek universe. The Tyranids could be seen as an extremely hostile alien force that the Federation has to deal with. Their bio - ships and swarming tactics would be a huge contrast to the more technological - based Starfleet.

One idea could be inserting yourself as a new recruit in a Space Marine chapter. You could experience the brutal training and the strict code of honor. Another is to be a tech - priest, exploring the complex machinery and the religious aspects tied to it. Maybe even be a rogue trader, traveling the galaxy in search of profit and adventure.

Another interesting concept is to have a Primarch face a completely new enemy. Not the usual chaos forces or xenos, but something from within the Imperium itself that has turned against it. This would create a lot of internal conflict and moral dilemmas for the Primarch to deal with.