One possible interesting plot could be the little girl befriending Jeff in a very unexpected way. Maybe she finds him when he's injured and instead of being scared, she tries to help him. This could lead to a strange bond where Jeff has to protect her from other threats in his dark world.
Perhaps a plot where the little girl has some sort of special power that attracts Jeff. For example, she can see things that others can't, and she starts to see Jeff's past and the reasons behind his actions. This could make Jeff question his own existence and his actions towards others.
Another plot might involve a love - hate relationship. Pinkamena and Jeff the Killer could start off hating each other due to their different natures. But as the story progresses, they gradually find some common ground and start to have some strange feelings towards each other. This kind of complex relationship can add a lot of drama to the fanfiction.
Well, a plotline might involve the little sister being in a constant struggle between her loyalty to Jeff and her own sense of right and wrong. She might also be hunted by the same people who are after Jeff, which would add a lot of tension to the story. And she could form an unlikely alliance with someone who initially wants to kill Jeff but then realizes she can be a force for good in the situation.
One possible plot could be that the protagonist in the fanfic is on a mission to stop Jeff the Killer from his killing sprees. They form an unlikely alliance with other characters who have also been affected by Jeff. They then engage in a series of cat - and - mouse games with Jeff, which is full of suspense and danger.
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.
One interesting plot could be the reader moving into a new neighborhood where Jeff the Killer is rumored to lurk. The reader starts experiencing strange things like seeing a pale face in the window at night. Another plot might involve the reader being kidnapped by Jeff and having to find a way to escape while also trying to understand his motives. There could also be a plot where the reader is a detective trying to solve the mystery of Jeff the Killer and ends up getting too close to him.
One interesting plot could be them teaming up against a common enemy in the creepy world they inhabit. Maybe a new and more menacing slasher figure shows up, and they have to put aside their differences to fight it.
The main characters are Jeff the Killer and the little girl. Jeff, with his terrifying nature, and the little girl, who might be portrayed as either very brave or very naive. There could also be side characters such as the neighbors of the little girl who start to notice strange things happening around her since Jeff entered her life.
A different plotline could be set in an alternate universe where Jeff and Nina are not killers. They meet in a more normal setting, like a school or a small town. However, their dark pasts or tendencies start to surface, and they have to deal with how this affects their new - found relationship, all while trying to keep their true selves hidden from the people around them.
One interesting aspect could be the exploration of Jeff's insanity in different scenarios. For example, how his madness affects his interactions with other characters in the fanfiction world. Maybe it shows how his deranged mind views his victims or how he copes with his own inner demons.
In 'jeff the killer baby fanfiction', the creativity in the plot twists can be really engaging. For example, the baby version of Jeff could have powers or abilities that are different from the original character. It could also play with the idea of how other characters in the Jeff the Killer universe interact with this new baby - like incarnation. They might be initially less threatened but then realize the true danger.