Often, there is a backstory revealed about the kidnappers. Maybe they were wronged by Gil's family in the past, and this is their way of getting revenge. This adds depth to the story. Also, Gil might find an unexpected ally while kidnapped. It could be another captive who has been there for a while and knows the ropes. Together, they could come up with a plan to escape or at least send a signal to his friends. The rescue mission by his friends usually involves a lot of action, like sneaking into a heavily guarded place where Gil is being held.
One common plot point is the reaction of his friends. They are usually shocked and immediately start planning a rescue. For instance, Uma might use her pirate skills to track down the kidnappers. Another plot point could be Gil's own state of mind while kidnapped. He might be scared at first but then start to think of ways to escape. Sometimes, the kidnappers demand a ransom, which leads to a whole new set of problems for the other characters to deal with.
In many fanfictions where Gil gets kidnapped, it could be for various reasons. Maybe it's by a rival group who wants to use him as a bargaining chip against his friends. For example, in some stories, Uma's crew might be targeted because they are seen as a threat in the Isle of the Lost. Gil, being a part of that crew, gets kidnapped. Writers often use this plot device to create drama and show the loyalty and courage of the other characters as they try to rescue him.
A common plot point is the immediate reaction of his friends. They usually go into a state of shock and then quickly shift to determination to rescue him. Another is the discovery of clues. There might be a piece of clothing left behind or a strange symbol at the kidnapping scene. Also, there could be some sort of ransom demand, which would add more complexity to the story.
One possible fanfiction could be that Gil is exploring an old, abandoned part of the Isle and accidentally trips over some debris and hurts his leg. His friends, like Uma and Harry, then have to figure out how to get him back to safety and treat his injury.
Well, perhaps Gil is out fishing on the edge of the Isle and a sudden storm hits. A large wave knocks him off his feet and he hits his head on a rock. This could lead to a story about his friends trying to nurse him back to health while also dealing with their own fears about his condition.
One idea could be that Harry and Gil go on a treasure hunt that was hinted at in Descendants 2 but never fully explored. They could encounter new magical creatures and face challenges together, strengthening their bond as friends.
One plot idea could be that Harry and Gil go on a secret adventure outside of the Isle of the Lost. They discover a hidden treasure map and have to work together to solve the riddles and find the treasure. Along the way, they face various challenges like avoiding capture by Auradon guards who mistake them for troublemakers.
One common plot point is that Naruto's sickness becomes a threat to the village. Since he's often seen as a protector, his being incapacitated can make the village vulnerable. Another is the way his friends react. They usually band together to support him, like Sasuke might return to the village out of concern for Naruto's health. Also, the search for a cure can be a big part of the plot. It could involve seeking out rare herbs or consulting with ancient medical ninjas.
Sometimes, the plot twist is that Stiles is actually in on the kidnapping in a way. Maybe he's trying to protect his friends from a greater danger by faking his own kidnapping. So all the while his friends are searching for him, he's actually on a secret mission of his own, which is revealed later in the story and makes for a really interesting read.
One common plot twist could be that the kidnapper is someone Allen thought was a friend all along. It adds a sense of betrayal and shock to the story.
In some fanfictions, a plot twist could be that Haruhi's kidnapping is part of a virtual reality game that she unknowingly entered. The 'kidnappers' are just players in the game who are trying to win by capturing her. Another common plot twist is that the kidnapper has a change of heart halfway through. They start to see Haruhi's good qualities and instead of harming her, they end up helping her. And sometimes, it could be that the kidnapping is a test set by a mysterious organization to see if Haruhi is worthy of some special task or knowledge.