In fanfiction, Red X might have some form of power - enhancing device or trick that gives him an edge over Starfire. This could be the reason she struggles in his grip. Also, he could be using her friends as hostages in a way, and Starfire's love for her friends would make her struggle in his grip as she tries to find a way to save them without compromising her own values.
The difference in their moral compasses. Red X is more likely to cross ethical lines. Starfire, with her strong sense of right and wrong, would find it hard to be under his control in his grip, as it would go against her principles.
In fanfiction, Starfire might struggle in Red X's grip due to their opposing natures. Red X is often depicted as a more morally ambiguous character compared to Starfire's pure - hearted self. His grip could symbolize her being caught in a situation that challenges her beliefs and values.
Other minor characters from the Teen Titans universe might also make an appearance. Maybe some of the villains that are associated with Red X could be there in the background, influencing his actions towards Starfire. Or some of the civilians that the Teen Titans protect, who could be caught in the crossfire of this struggle between Starfire and Red X, and their presence could add more complexity to the story.
A lot of fanfics might focus on a mission or adventure that they go on together. This gives the opportunity for them to bond and develop feelings for each other in the face of danger.
One common theme is trust. Since Red X is a rather mysterious character, Starfire often has to learn to trust him or not. For example, in many fanfics, they start off as distrustful of each other but gradually build trust as they face challenges together.
One characteristic is the exploration of their opposing personalities. Red X is more of a anti - hero, while Starfire is a heroic and positive character. Fanfictions may focus on how they clash or find common ground. For example, they could be forced to work together on a mission, and during that time, they start to see each other in a new light. Maybe Red X shows a softer side that Starfire didn't expect, or Starfire's optimism starts to rub off on Red X. Also, the fanfictions might delve into the power dynamics between them, considering their different abilities and how they complement or conflict with each other during battles or other situations.
You can try searching on fanfiction platforms like FanFiction.net or Archive of Our Own. Just use the keywords'red x kidnaps starfire' in their search bars. There might be some great stories out there that match this plot idea.
Red X might be motivated by revenge. Maybe Starfire had previously thwarted his plans, and he's getting back at her by tying her up with the slime.
You can try searching on fanfiction websites like Archive of Our Own (AO3). It has a large collection of fanfics from various fandoms, and you might be able to find some great Starfire x Red fanfics there by using the search function.
One great Red X and Starfire fanfic could be a story where Red X is initially a villain but slowly starts to have a change of heart due to his interactions with Starfire. Their relationship could be filled with tension and mystery as they try to understand each other's motives.
One way could be to use 'Red X' as a mysterious force that is somehow related to 'red glue binding'. For instance, the Red X could be the key to activating the red glue binding spell.