Captain Hook would initially feel victorious. But then he might realize that Peter was an important part of Neverland's balance. Without Peter, the eternal battle that gave his life purpose is gone. He could start to feel lost and even a bit regretful for all the times he tried to kill Peter.
Stray Kids, on the other hand, would also be very concerned. Bang Chan, as the leader, would take charge. He might start asking questions to figure out what exactly happened. Felix could be bringing water or something to make Y/N feel better. Lee Know would be standing guard, making sure no further harm comes to Y/N while they are in a vulnerable state.
Peter could become very angry. He might seek revenge on whoever or whatever he blames for Tinkerbell's death. He could go on a rampage through Neverland, looking for the cause of her death and not stop until he has some form of retribution.
Y/N should have their own goals and dreams. If they're interested in becoming an Auror, that can shape their actions and decisions. Their reactions to Draco should be based on their personality. If they're a shy person, they might be more hesitant around him. And make sure their dialogue is natural. Don't make them say things that are out of character just to move the plot along. For instance, if Y/N is a studious type, they're more likely to talk about books or spells when interacting with Draco.
As time passes, Wendy might start to feel a sense of responsibility towards the Lost Boys. Even though she was kidnapped, she realizes they are just lost children. So, she could start to take on a motherly role, teaching them manners and telling them stories. This would be her way of making the best of a bad situation and also showing her kind heart.
Peter Pan is in love with Wendy. Wendy's arrival in Neverland changes things for Peter. She brings a sense of warmth and home - like feeling. Peter is drawn to her because she has qualities that are lacking in Neverland. She can cook, tell stories, and provide a nurturing presence. Peter's love for Wendy is shown through his eagerness to have her stay in Neverland and be part of his world, although he doesn't fully understand the nature of adult - like love.
They might immediately stop the concert. The members would be really worried. For example, Jin could rush over to where Y N is with a concerned look on his face. He might ask the medical staff what's wrong and offer words of comfort.