Another development could be that the dragon actually needs Hiccup's help. Maybe the dragon is injured or has a problem in its lair that only a human can solve. So, instead of harming Hiccup, it keeps him captive until he can fix the issue. This could lead to a very interesting relationship between them.
Well, one plot development could be that Hiccup uses his wits to escape. He might study the dragon's behavior while captive and find a weakness to exploit. For example, if the dragon has a particular routine when it leaves the lair to hunt, Hiccup could use that time to make his escape.
In this fanfiction, perhaps Harry is kidnapped by the Order because they think he's being influenced by dark forces. As the story unfolds, he could start to understand their reasons while also uncovering a traitor within the Order who wants to harm him for real. Or, he might use his skills to turn the situation around and make the Order see that they were wrong to kidnap him in the first place. He could then lead them in a new direction against Voldemort.
Well, one possible plot development could be that the kidnappers demand a ransom from Batman. Batman then has to race against time to find Robin without alerting the media or causing panic in Gotham. Another development might be that Robin manages to leave some hidden clues for Batman to find while being held captive. Maybe he uses his martial arts skills to briefly overpower one of the kidnappers and mark a symbol on the wall that only Batman would understand.
One possible plot development could be that Duke's friends in the Bat - family immediately start a search operation. They might use their various skills and resources to track down the kidnappers. For example, Batman could analyze the crime scene for any clues while Robin tries to hack into security cameras in the area.
In this fanfiction scenario, Naruto's unique abilities like his shadow clones and rasengan would be interesting to see in the context of being kidnapped by Rias Peerage. Maybe the Peerage kidnapped him because they saw his power and wanted to use it for their own purposes. Naruto might resist and start training in secret to get stronger and break free. He could also form an alliance with other characters who oppose Rias Peerage in their world.
One possible plot development could be Naruto struggling to control his new dragon powers. He might accidentally cause destruction in the Hidden Leaf Village at first. Then, he'd have to go on a journey to learn how to master these powers, perhaps with the help of an old sage or a mysterious dragon - like creature.
Well, perhaps in the fanfiction, Sakura is kidnapped by Sasuke because he wants to use her as a bargaining chip against Konoha. Then, the story could involve the other Konoha ninjas coming together to strategize a rescue mission. They might have to deal with Sasuke's new and powerful abilities that he has acquired during his time away. Sakura, while kidnapped, could also try to talk some sense into Sasuke, appealing to their past friendship and her feelings for him.
One possible theme is friendship. The relationship between Hiccup and his dragon is a strong form of friendship. They rely on each other, trust each other, and grow together.
Well, it could involve rescue attempts by other characters, or maybe you have to find a way to escape on your own while uncovering the kidnapper's motives.
In this fanfiction scenario, it's likely that Stiles' Omega nature plays a crucial role. Maybe Kate is specifically targeting him because of his unique position in the pack. Stiles could be held in a place filled with various supernatural traps and obstacles. His friends, like Scott and Lydia, would be frantically trying to find him. They might have to face off against Kate's allies as well. As Stiles endures his captivity, he could be learning more about Kate's motives and secrets, which could potentially be used against her when he is rescued.
It could go a few ways. Maybe the friends of Hiccup form a rescue team and come up with a strategic plan to find and free him. Or, there could be some unexpected twist where Hiccup manages to escape on his own with the help of a dragon. It all depends on the creativity of the author.