In this fanfiction scenario, Goku might end up having to fight Broly while being kidnapped. Since Goku is always up for a good fight, he could use this as an opportunity to test his new powers or techniques against Broly. On the other hand, the Z - Fighters back on Earth would be worried sick. Chi - Chi would be fuming and ready to take matters into her own hands if the others don't act fast enough. Krillin and the others would also be strategizing on how to free Goku without getting him hurt.
Well, one possibility is that Goku's friends would immediately start a search and rescue mission. Vegeta, being his rival but also an ally, would probably be at the forefront. He'd be furious that Broly dared to kidnap Goku. They'd likely track Broly's energy signature to wherever he's taken Goku. Another thing could be that Goku, while kidnapped, tries to reason with Broly. Maybe he discovers that Broly has some deeper issues or motives for the kidnapping that could potentially be resolved through conversation.
Perhaps Vegeta kidnaps Goku to get some secret training method from him. Vegeta is always eager to become stronger, and he might think Goku has some hidden knowledge that could help him surpass his limits. So he takes Goku to a secluded place to force the information out of him.
Goku could escape by overpowering Broly. He might tap into his Super Saiyan forms, like going into Super Saiyan Blue or even Ultra Instinct if he's pushed far enough. His sheer power and fighting skills could allow him to break free from whatever restraints Broly has put on him.
Another aspect could be the emotional turmoil for the other Avengers. They would surely be scrambling to find Tony. Captain America might feel especially guilty, considering their past differences. The team would have to put aside their differences completely to rescue Tony. They might start by gathering intel on Thanos' whereabouts and formulating a plan that involves their unique skills. For example, Black Widow could use her espionage skills to infiltrate Thanos' base, while Thor could provide the brute force needed in a direct confrontation.
One possibility is that Naruto's friends would immediately launch a rescue mission. They would likely gather intel about Kumo's motives and whereabouts. For example, Sasuke might use his Sharingan to track any clues left behind. Sakura would prepare medical supplies in case of injuries during the rescue.
One possibility is that her friends, like Percy, would immediately start a rescue mission. They would likely gather all the resources and allies they could find. Maybe they'd consult the Oracle for some clues on where Kronos has taken Annabeth.
Perhaps Madara has some ulterior motives for kidnapping Hinata. He might want to use her as a bargaining chip against the Hidden Leaf Village. Or he could be interested in her unique abilities. In that case, the Hidden Leaf would have to decide whether to meet Madara's demands or try to outwit him to get Hinata back safely.
Well, one possibility is that Elena's friends would immediately start a search party. Damon, for instance, would be furious and stop at nothing to find her. He might enlist the help of Stefan and Bonnie. They could use Bonnie's magic to try and track Klaus' whereabouts.
In a scenario where Orochimaru kidnaps Hinata, the Hyuga clan would surely get involved. They'd be outraged and use all their resources to find her. Orochimaru might be interested in Hinata's Byakugan for his experiments. He could try to extract its power or study it. But Hinata has been trained in the Gentle Fist style, so she might be able to hold her own against Orochimaru's minions for a while. And who knows, Sasuke might also get involved. He has his own history with Orochimaru and might see this as a chance to confront him again, especially if he realizes that an innocent like Hinata is in danger.
One possibility is that Naruto and the others would immediately start a search and rescue mission. They would follow Sasuke's tracks and try to figure out his motives. Sakura, on the other hand, might try to reason with Sasuke during the kidnapping. She could remind him of their past friendship and the bonds they once shared.
In a fanfiction where Esdeath kidnaps Tatsumi, one possibility is that she tries to force him to join her side. She might use various means like threats against his friends or promises of power. Tatsumi, being a hero at heart, would likely resist. He could try to escape while also trying to figure out Esdeath's weaknesses to defeat her later.