At first, he may be in shock. He can't believe that he's being kicked out of the place he's fought so hard to protect. He might try to reason with the camp leaders, but when that fails, he becomes determined. He decides that he'll continue his mission of protecting the world on his own terms. He'll still care about the camp from afar, but he'll focus on building his own strength and resources so that he can either come back on his own terms or be a force to be reckoned with even from the outside.
Percy could also be very sad. He has so many memories and relationships at the camp. He might go into a state of depression for a while, not knowing where to go or what to do next. But then, he would probably start to think about how to get back in or how to make things right. He might start looking for evidence to clear his name if he was wrongly accused. He could also look for new allies outside of the camp who could help him in his situation.
He might be really angry at first. He's given so much to the camp, and being kicked out like that without a proper explanation would make him furious. He could storm off, vowing to find out the truth and clear his name.
Stiles might be initially shocked. He would probably feel betrayed since he thought of the pack as his family. He could go into a state of denial at first, not believing that they would actually kick him out.
One reason could be if he was wrongly accused of stealing something important from the camp. Maybe a powerful magical item goes missing and Percy is the prime suspect because of his past issues with authority. Another reason might be if he accidentally endangers the camp in some way during a mission or training exercise. For example, if he unknowingly leads some dangerous monsters back to the camp.
Well, initially Percy would be confused. He would try to understand why someone he trusted would turn on him. Depending on the severity of the betrayal, he might isolate himself for a while, thinking that he can't trust anyone. But as he is Percy, he would also start to look for a way to clear his name and prove his innocence. He would use his wits and his skills to figure out what really happened and expose the truth. He may also have some internal struggle about whether to forgive the betrayer if the situation allows for it.
Sora might be initially confused. He has always been on a journey to help different worlds, so being kicked out would be unexpected. He'd probably try to reason with the people kicking him out, asking them why and trying to clear up any misunderstandings.
He might be really angry at first. Natsu is a passionate character, and being kicked out unjustly would make him furious. He could storm off vowing to prove his worth and show the guild they made a mistake.
A plot could be that Percy accidentally breaks an ancient and sacred rule of the camp while trying to save a fellow camper. As a result, he's kicked out. He then decides to seek refuge with his mortal family, but soon realizes that monsters are targeting them too because of his connection. So he has to protect his family while also finding a way to get back into the good graces of the camp.
He might be initially in shock. Percy has been through a lot with Annabeth, so being dumped would come as a huge blow. He could be speechless for a while, unable to process what has just happened.
Natsu would probably be very angry at first. He loves Fairy Tail like a family, so being kicked out would feel like a huge betrayal. He might go on a rampage, shouting and arguing with the guild members who made the decision.
Lucy might be heartbroken. After all, Team Natsu was like a family to her. She could initially go into a state of shock and disbelief. Maybe she would try to plead with the team to let her back in, explaining that whatever they thought she did was a misunderstanding.