One common theme is the power dynamic. Jeff is often portrayed as the dominant and menacing force, while Sally is more of the victim or the one trying to resist his dark influence.
There are often themes of the struggle between good and evil. Sally is usually seen as the 'good' or more innocent character, while Jeff is the epitome of evil. The fanfics may show Sally's attempts to either escape from Jeff or to somehow find a way to co - exist with him. Also, themes of psychological manipulation can be common, as Jeff might use his terrifying presence to manipulate Sally's emotions and actions.
One common theme is the power struggle. Since both Jeff and Nina are killers, there can be a battle for dominance in the fanfic. Also, the theme of unrequited love sometimes pops up, with Nina loving Jeff but not always getting the same in return. And of course, the general horror theme of blood and gore is often there as it's part of their nature as killers.
Love - hate relationship is also very common. They are enemies by nature but in some fanfics, there's an underlying attraction or connection that they can't deny. This creates a lot of drama and tension in the stories.
Isolation is also a theme that might come up. Both characters are often depicted as being alone in their own terrifying worlds. In the fanfic, their meeting could either break that isolation or intensify it. And there's the theme of the unknown. The reader is always left wondering what these two will do next, especially when their powers and motives are so unclear.
One common theme could be the struggle between good and evil, especially considering Pinkamena's somewhat ambiguous moral standing and Jeff the Killer's clearly villainous nature. Another might be the idea of redemption or the lack thereof in their relationship. Also, themes of madness and chaos often come up as both characters are associated with rather unhinged behaviors.
Well, a frequent theme is the exploration of their individual characters. Sally's child - like qualities and Jeff's, well, his own unique traits. And sometimes, there's the theme of protection. Jeff might protect Sally in a dangerous situation or vice versa. It adds an emotional depth to the story. There are also stories that play around with the idea of them being in a different world or time, which is quite cool as it allows for a lot of creativity in the plot.
One common theme is the exploration of the dark side of human nature. Since both Jeff the Killer and Ben Drowned are from rather dark and disturbing origins, their stories often delve into this aspect.
A prevalent theme is the idea of an unlikely partnership. Given their different natures, fanfics often play around with how they might come together, whether it's for mutual survival or some other strange reason. For instance, they might team up against a more powerful evil in their world. It also explores the power dynamics between them, as Jeff is more impulsive while Eyeless Jack is more calculating. Another theme is the psychological aspect of their relationship. How do their minds, which are both damaged in their own ways, interact? Do they find some sort of understanding or is it just a constant battle of wills? This is often explored in great detail in many 'eyeless jack x jeff the killer fanfic'.
It has a certain level of popularity. In the horror fanfic world, people like to experiment with different character pairings. Jeff the Killer is a very recognizable and menacing figure, and Sally has her own tragic backstory. Combining them in a fanfic can lead to some really unique and often disturbing, but in a good way for horror fans, stories that attract a fair share of readers.
Another plotline might involve Sally and Jeff going on a journey together to find a way out of the nightmarish place they are in. Along the way, they face various challenges that test their relationship. Jeff's killer instincts might conflict with Sally's more innocent and hopeful nature, but they learn to work together and in the process, their bond deepens.
One common theme is the struggle between good and evil. Jane is often portrayed as more of the 'good' side trying to stop Jeff who is seen as the 'evil' one. So there's a constant battle of morals.