The guild master, Makarov, would be deeply concerned. He might use his own magic to try and stabilize Natsu's condition. Some of the more impulsive members like Natsu's friends might want to take immediate revenge on whoever or whatever they think caused the heart attack. Meanwhile, characters from other guilds who are friends with Natsu might come to offer their assistance, bringing with them their own unique magics and resources to help save Natsu.
Natsu's friends would have a range of reactions. Lucy would be distraught, her face pale with fear as she kneels beside Natsu. Gray would clench his fists, his eyes filled with rage as he scans the area for the shooter. Erza would be the voice of calm and reason, though her hands would be shaking slightly as she tries to stop the bleeding. Happy would be flying around in a frenzy, screeching in distress. They would all be united in their determination to save Natsu and seek justice for what has happened.
Gray would probably be one of the first to want to go after Natsu. He and Natsu have a long - standing rivalry but also a deep friendship. He'd be furious and determined to rescue Natsu. Lucy would be very worried too. She might use her celestial spirit magic to try and find Natsu's location. Erza would be very focused and strategic, rallying the rest of Fairy Tail to come up with a rescue plan.
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.
Li Shang would probably be very concerned. He might blame himself for not protecting her better. He would immediately call for the best medical help available and stay by her side until she recovers.
He could also react with confusion. Natsu is a bit of a simple - minded character in some ways, and he might not understand why someone would want to bully him. This confusion could lead to him trying to figure out the bully's motives.
When Natsu gets angry in the fanfiction, different characters have different reactions. Erza, being the strong and authoritative figure in the guild, would likely try to discipline Natsu in some way, but also understand that his anger often comes from a place of protecting his friends. Wendy would be a bit more timid in her approach. She might use her healing magic to try and calm Natsu's emotions, as she can sense the turmoil in his magic energy. And Makarov, the guild master, would probably give Natsu a stern look and a lecture about controlling his temper.
Yuki would likely be very concerned. He has a soft spot for Tohru and would probably rush to her side, trying to find a way to help. He might even blame himself if he thinks he could have prevented it. Kyo, on the other hand, would initially be angry, but that's just his way of showing worry. He would be more hands - on in getting her the help she needs.
The people of Arendelle would be in a state of chaos and mourning. Elsa has been their queen and their protector. Some might be afraid that without Elsa, the kingdom would be vulnerable to new threats. The trolls, who have known Elsa since she was a child, would also be deeply saddened. They might try to find a way to bring her back, using their own magic and knowledge. Sven, Kristoff's reindeer, would sense the change in Kristoff's mood and would be more subdued, staying close to his owner during this difficult time.
His friends would likely be very concerned. They might immediately rush to his side to check on his injuries. For example, they could call for medical help or try to stop any bleeding if it's a more serious wound. They would also offer words of encouragement and support, telling him not to worry and that he'll get better soon.
Lee would be devastated if he were still alive. He would do everything in his power to save her, like searching for a doctor or medicine. He would be by her side constantly, giving her words of encouragement.