One idea could be a crossover with a popular superhero universe. Jeff the Killer could find himself in a city full of superheroes and villains. He might initially be seen as a threat but then has to team up with some heroes to fight a greater evil. Maybe he uses his stealth and killing skills in a different way to help save the day.
A crossover with a horror game like Silent Hill could be really cool. Jeff could wander into the fog - filled streets of Silent Hill. He'd encounter the nightmarish creatures there. And perhaps there's a mystery that links his own past with the dark secrets of Silent Hill that he has to uncover while also trying to survive in this new terrifying world.
How about a crossover with a post - apocalyptic world? Jeff the Killer in a world where society has collapsed. He could either be a lone wolf trying to survive or get involved with a group of survivors. There would be new challenges like fighting off mutated creatures and other desperate humans. His killer instincts might be an advantage in this harsh new environment.
Maybe Ben Drowned uses his digital powers to help Jeff the Killer get revenge on someone who wronged him in the past. Ben could manipulate technology to create diversions while Jeff goes in for the kill. It could be a story of an unorthodox friendship formed through mutual goals.
One idea could be that a girl moves into a town where Jeff the Killer is known to lurk. She's a bit of an outcast and for some reason, Jeff becomes intrigued by her. Instead of killing her immediately, he starts leaving little signs of his presence around her, like a strange flower on her windowsill. Eventually, they start to communicate in a very unusual way, through notes left in the forest.
A plot could involve Jeff the Killer being a part of an experiment by Orochimaru. Orochimaru, always interested in unique and powerful beings, tries to combine Jeff's dark powers with some ninja techniques. Naruto and his friends then have to stop Orochimaru's new creation, which is a half - Jeff, half - ninja monstrosity. Along the way, Naruto tries to reach out to the human side of Jeff.
One idea could be that Jeff the Killer becomes an apprentice of Slenderman. He learns the more supernatural and strategic ways of hunting from Slenderman. Another could be a story where they have to team up against a common enemy, like a powerful group of demon hunters who are after both of them. Or perhaps a plot where Jeff the Killer starts to question his own murderous ways after spending time with Slenderman, who has a more calculating and long - term approach to his actions.
One idea could be that Jeff and Jane are forced to team up against a common enemy in a spooky forest setting. As they fight side by side, they start to see each other in a different light. Another could be a time - travel plot where they end up in a different era and have to adapt together. And perhaps a plot where they both get trapped in a haunted mansion and have to find a way out while dealing with their complex relationship.
Some interesting ideas might include how the pregnancy came about in the first place in the context of the 'Jeff the Killer' world. Is it some sort of dark magic or a strange encounter? And then there's the aspect of how this pregnancy might change the power dynamics between Jeff and other characters. Maybe she becomes more vulnerable and has to rely on unexpected allies.
One plot idea could be that Slenderman and Jeff the Killer are forced to team up against a common enemy, like a powerful demon. As they work together, they start to understand each other's motives and develop an odd friendship that has hints of a deeper relationship. Another idea is that they find themselves in a strange dimension where they have to rely on each other to survive, and during this time, their relationship blossoms in unexpected ways. A third plot could be that they are both haunted by their pasts and find solace in each other's presence, leading to a relationship that defies the norms of their murderous existences.
A possible plot could be that Jeff has a dream where he meets Slenderman. In the dream, Slenderman offers him a chance to become even more powerful. Jeff is tempted and when he wakes up, he starts to search for Slenderman in the real world, leading to a journey full of strange encounters and self - discovery.
One idea could be that they team up to take on a common enemy in a post - apocalyptic world. Their relationship starts off rocky but as they face challenges together, they develop a deeper bond. Maybe Eyeless Jack has some hidden powers that Jeff discovers during their battles.
One interesting plot could be their unexpected alliance. Maybe they are forced to team up against a greater evil in the fanfic. This would create a lot of tension as they have their own issues with each other but have to put them aside for the common good.