Bobby could also be a key figure. He's like a father figure to the boys and has a wealth of knowledge. He might know of some old remedies or be able to point them in the right direction to find a way to heal Dean. Charlie could also pitch in. She's smart and resourceful and could use her hacking skills to find information related to Dean's injury.
Katara would be a likely character to help Toph recover. Katara is a waterbender and has healing abilities. She would use her skills to tend to Toph's injuries, whether they are physical wounds or internal damage from overusing her earthbending. Another one could be Aang. He's the Avatar and has a deep connection with all the elements. He might use his spiritual knowledge to help Toph heal faster, maybe by finding a special place for her to rest and regain her strength.
Even some of the antagonists could potentially help Jaune if there is a complex relationship developed in the fanfiction. For example, if an enemy realizes that Jaune's death or continued injury would disrupt some sort of balance, they might step in to heal him, albeit reluctantly.
Sasuke is very likely to be involved. Given their complex relationship, Sasuke could be the one who finds Naruto severely injured and has to make a choice between helping him or leaving him. Another character could be Sakura. As a medic - ninja, she would be the one to try and heal Naruto's severe injuries. Kakashi too might be involved, either as a mentor figure who tries to figure out what happened to Naruto or as someone who has to step in to protect Naruto from further harm while he is injured.
The Hokage at the time, whether it's Tsunade or someone else, would likely get involved. They would allocate resources and ensure that the best medical care is provided. Additionally, some of the older ninja who knew Kakashi since he was young, like Iruka, might offer moral support and assist in any way they can, like gathering information or running errands related to his treatment.
In some fanfictions, Naruto's recovery could be a long and arduous journey. He might have to go through intense physical and mental training while recovering. The author could also introduce some kind of ancient and forgotten medical knowledge that is used to treat his severe injuries. His recovery might also be tied to some prophecy or hidden power within him that is awakened due to the near - death experience.
His teammates are very likely to help. Kagami, for instance, might push him during rehabilitation exercises in a tough - love kind of way. The other members of Seirin could also offer moral support, like bringing him his favorite snacks or just spending time with him. His coach too could be involved, providing expert advice on how to come back stronger.
Venom could be another one. He has a vendetta against Spiderman, and knowing he's injured, he would likely try to finish him off once and for all. He could lurk in the shadows waiting for the right moment to attack.
The other dragon riders could also be in the fanfic. Fishlegs could use his knowledge of dragons and other lore to figure out if there's a dragon - related way to heal Astrid. Snotlout might initially seem more concerned with his own status but would probably end up helping in his own way, perhaps by providing some muscle when needed for tasks related to Astrid's care.
Sakura would definitely be involved. As a medical ninja, she would be at the forefront of trying to heal Naruto. Sasuke might also be there, either helping in the fight that led to Naruto's injury or coming back to the village to see his old rival. Kakashi would also be around, using his experience to strategize how to protect Naruto while he's injured.
Hermione could be a main character. She would use her vast knowledge of magic to try and find a cure or treatment for Ginny's injury. Luna Lovegood could also be important. She might have some unique insights or magical remedies that could help Ginny. And of course, Ginny's parents, Arthur and Molly Weasley, would be main characters. They would be extremely worried and do everything in their power to take care of their daughter.