One way for the kidnapped character to escape is by outsmarting Sasuke in a battle of wits. If they can make Sasuke believe that they are more useful to him alive and free, he might let them go. They could also try to form an alliance with other forces that are against Sasuke's actions. For instance, if there are other ninjas who are looking for the kidnapped character, they could coordinate with them to create an opportunity for escape. Additionally, the kidnapped character could try to gain Sasuke's trust over time and then use that trust to their advantage when the time is right.
The kidnapped character could use their own hidden jutsu skills to break free. For example, if they have a teleportation jutsu they've been hiding, they could use it when Sasuke is distracted. Another way is to appeal to Sasuke's emotions. If they can remind him of his better nature or a past event that made him more empathetic, he might let them go.
They could use their ninja skills. Sasuke might use his Sharingan to find weaknesses in their captors' defenses, and Sakura could use her superhuman strength to break through any physical barriers. Maybe they work together to create a diversion and then make a run for it.
Sakura could use her medical ninjutsu skills to create a distraction. For instance, she might make it seem like she's poisoned herself, causing Sasuke (or whoever is involved in the kidnapping) to get closer, and then she could attack and escape.
Hinata could use her Byakugan to find weaknesses in Sasuke's defenses. Maybe she spots a chakra - based trap that she can manipulate to create a distraction and then make her escape. She could also use her Gentle Fist techniques in a creative way, like redirecting Sasuke's attacks back at him to create an opening for her to run.
They might find an ally within the place where they are held. There could be another being there, maybe an angel who doesn't agree with Castiel's actions, or a human who has also been captured by Castiel in the past and knows the layout well. Together, they could come up with an escape plan.
One possible plot could be that Sasuke has a hidden agenda. Maybe he believes Naruto is in danger from a new, unseen enemy in the ninja world. So, instead of explaining his reasons to Naruto, he kidnaps him to keep him safe in a secret location. However, this action might be misinterpreted by their friends, leading to a search and rescue mission.
In many Sasuke - Sakura fanfictions, a kidnapping plot can add a lot of drama. If Sasuke kidnapped Sakura, it could be due to various reasons. Maybe he was influenced by some dark power that made him lose his rational thinking and see Sakura as a key to something he wants. This kind of plot often leads to a series of events where Sakura has to face her feelings towards Sasuke in a very extreme situation, like trying to understand his motives while also being scared for her own safety.
Perhaps Sasuke has been influenced by some dark force. This force could be manipulating him into believing that Naruto is a threat to his goals. So, he kidnaps Naruto to either stop him from interfering or to convert him to his side. It could lead to a very intense struggle within Naruto to resist Sasuke's influence.
The kidnapped character might first show fear, especially if they don't understand Spock's motives. But then, they could start to analyze the situation. If they are a scientist or an engineer, they might try to use their skills to find a way out. They could try to disable the ship's systems that Spock is using to keep them captive. And if they have some knowledge of Vulcan culture, they could try to appeal to Spock's sense of honor and loyalty to Vulcan values, perhaps by reminding him of the importance of non - aggression and respect for life.
Sasuke's character could develop in terms of his ninja skills. If Itachi kidnaps him, perhaps he will be forced to train in a new and harsher environment. This could make him stronger not only physically but also mentally. He might learn new jutsu or improve his existing ones at a much faster rate. Also, his understanding of the Uchiha clan's history and power could deepen during this time, which would shape his identity as an Uchiha.
Percy could look for any weaknesses in the wizards' magic or their security. Maybe there are certain times of day when their spells are less effective. He could also try to befriend a less - strict wizard who might be willing to help him escape.