A more complex plot idea might be that an old enemy from Riddick's past resurfaces and kidnaps Jack to lure Riddick into a trap. Riddick then has to use all his wits and strength to rescue her. Along the way, he discovers that the enemy has some new and deadly technology. He has to fight not only the enemy's minions but also figure out a way to disable the technology to save Jack and himself.
Another plot could revolve around Riddick trying to teach Jack some of his survival skills. He shows her how to track in the dark, use minimal resources for maximum effect. This could lead to a deeper bond between them as they face various challenges together. For example, they get trapped in a cave system and have to rely on each other to get out.
One plot idea could be that Pitch Black tries to use his darkness to corrupt Jack Frost's wintery world. Jack has to fight back using his ice powers and the positive energy of the season. Maybe they start as enemies but gradually come to understand each other's motives.
One plot idea could be that Pitch Black tries to use his powers of darkness to tempt Jack Frost into joining his side, but Jack resists. Their interactions could be filled with tension and drama. For example, Pitch might offer Jack power over winter in a different, more menacing way. Another idea is that they could be forced to work together to defeat a common enemy, and during this time, they start to understand each other better. This could lead to a slow - burn friendship or something more.
A possible plot could involve Jack Frost accidentally stumbling into Pitch Black's lair. Pitch Black, instead of attacking him immediately, decides to play with him a bit. He creates illusions and challenges for Jack. Jack, being the adventurous spirit he is, takes on these challenges, and through this encounter, both characters learn something new about themselves and each other. In the end, it could lead to a change in their relationship, perhaps a more nuanced understanding between the two.
Well, a fanfiction could explore what would happen if Jack Frost was somehow influenced by Pitch Black's darkness. Maybe Pitch Black tries to corrupt Jack, but instead, Jack finds a way to redeem Pitch Black. Or perhaps in a different take, they meet in a dream realm where the normal rules don't apply, and they have a strange and intense encounter that changes their relationship.
Their relationship could develop further if they start to understand each other's motives better. For instance, Jack may start to see the reasons behind Riddick's tough exterior. This could lead to more trust between them.
One popular theme is survival. Given the harsh and unforgiving environment in Pitch Black, fanfictions often explore how characters, especially Riddick, survive against all odds. Another theme could be redemption. Riddick has a complex past, and fanfictions might delve into his journey towards redeeming himself. Also, the theme of loyalty among the characters in the face of danger is quite common.
Another plot could involve Rapunzel's hair having the ability to repel Pitch Black's nightmares. Pitch discovers this and tries to cut off her hair. However, Rapunzel uses her wits and the help of Pascal and Maximus to outsmart him. In the process, Rapunzel realizes she has more power within her than she ever knew, not just in her hair but in her spirit, and she becomes a force to be reckoned with against Pitch.
Survival is a very common theme. Just like in the movies, the characters in fanfiction often find themselves in harsh and unforgiving environments where they have to fight to stay alive. Riddick himself is a symbol of survival against all odds.
Perhaps a plot where Pitch is injured and Jack, out of a sense of fairness or maybe just curiosity, decides to help him. This could lead to a strange bond forming between them. As Jack nurses Pitch back to health, Pitch starts to see Jack in a new light, not just as an annoying Guardian. And Jack gets to see the more vulnerable side of Pitch. This could create a lot of internal conflict for both characters as they deal with their new - found relationship within the context of their opposing natures.
Riddick, of course. He's got this mysterious and dangerous aura that makes him really interesting to write about. His past, his abilities, and his moral code all provide a lot of material for fanfiction writers. Another interesting character is Imam. His faith and how it guides him in the face of danger is a great aspect to explore in fanfiction.