Well, you could have a story where a long - lost technology from an ancient civilization on Farscape is discovered and there's an 'assault' in the sense of a race to obtain it. Different factions, including some old enemies of the crew, are all vying for this powerful device. It could also be an environmental assault, like a strange energy wave that starts to corrupt Moya's systems and the crew has to find the source and stop it before it's too late.
Maybe there could be an assault on the crew's values. They come across a planet where the inhabitants have a very different moral code, and this challenges the crew in unexpected ways. For example, they might be faced with a situation where they have to decide whether to sacrifice one of their own to save the planet, which is against their usual principles. This internal struggle could be a great focus for the fanfic.
One idea could be to focus on a new alien species attacking Moya. The crew has to quickly figure out the aliens' weaknesses and form alliances with other races they encounter in the Uncharted Territories. Another could be an internal 'assault' within the crew, like a conflict over resources that threatens to tear the group apart. Or perhaps a mind - control plot where an enemy assaults the minds of the crew members one by one.
I'm not sure specifically what this 'assault john farscape fanfic' is about as it could be a very niche or user - created piece. It might involve a character named John in the Farscape universe experiencing some form of assault within the context of the fan - written story.
There's no way to really know for sure if it's popular without looking at the stats on the fanfic platforms. However, given the rather specific and potentially disturbing nature of the title, it probably isn't one of the most popular Farscape fanfics. Most fans might be more interested in stories that expand on the show's existing storylines in a more positive or exciting way rather than one that focuses on an 'assault' scenario.
Maybe a character from Stargate, say Daniel Jackson, gets stranded in the Farscape universe. He could use his knowledge of ancient cultures and languages to help the Farscape crew with some of their own mysteries. And in return, the Farscape crew could teach him about their unique technology and ways of survival in a very different and often hostile galaxy.
A rogue Peacekeeper could be the main antagonist. This character could have been exiled or have a personal vendetta against one of the crew members. They might use their knowledge of Peacekeeper tactics to launch an assault on the crew, perhaps by leading a group of mercenaries or by using some underhanded means to get close to Moya and strike when the crew least expects it.
One idea could be exploring the backstories of the lesser - known characters in the 'Batman Assault on Arkham' universe more deeply. For example, you could focus on Killer Croc's life before Arkham and what led him to become the way he is. Another plot could involve a team - up between unexpected characters from the movie, like Harley Quinn and Deadshot, against a new threat in Arkham that the Bat - family is unaware of.
One idea could be exploring the backstory of the antagonists in more detail. Maybe there's a hidden motive or a tragic past that led them to oppose Star Fox. Another could be a story where the Star Fox team has to deal with a new, unexpected threat that is even more powerful than the usual foes they face. And a third idea is a story centered around a character from the team having to make a difficult personal sacrifice for the greater good of the galaxy.
Well, perhaps in the fanfiction, the SAS discovers a portal that leads to a different dimension full of zombie - like creatures but with unique abilities. They then have to use their military skills combined with the knowledge they gain from the new environment to survive and close the portal. They could encounter some local resistance fighters in that dimension who are also trying to fight the zombies, and they all join forces.
One popular 'farscape fanfic' story could be those that explore the untold adventures of the main characters in different galaxies. For example, some might focus on what would happen if a certain character made a different choice during a crucial moment in the original series.
Another plot could revolve around the characters having premonitions of the events that are going to occur in the quarry. They then have to decide whether to trust these visions and how to act upon them. This could add a whole new layer of suspense and mystery to the story.
One idea could be a time - travel plot. The Backyardigans accidentally find a magical object in the backyard that sends them to different eras in history. They could have to work together to find their way back home while also learning about the different time periods. For example, they might end up in the prehistoric era and have to deal with dinosaurs.