Even some of the school faculty could be responsible in a sense. For instance, a strict teacher who doesn't understand Danny's situation might push him too hard during detention or some other punishment, which could lead to an accidental injury. Or a science teacher's experiment could go wrong and Danny could get caught in the crossfire.
One possible scenario could be Danny getting bullied at school. Maybe some of the other students find out about his ghost powers and they target him out of fear or jealousy. Another could be that he gets injured during a ghost attack that takes place on school grounds while he's trying to protect his classmates.
A Danny Phantom hurt fanfiction could involve Danny getting hurt while exploring a new, dangerous part of the Ghost Zone. He might encounter some sort of toxic energy or a trap set by an evil ghost. His pain and struggle to get back to safety could be the main focus, and how he overcomes his injuries could show his strength and determination.
One idea is that Danny is hurt by a ghostly weapon that has some sort of curse on it. The curse slowly drains his energy and makes him weaker over time. His friends try to find a way to break the curse while Danny has to fight his own fading strength. Another idea could be that Danny gets injured while trying to protect someone he loves, like his sister Jazz. This could lead to some emotional moments between them as she tries to help him heal.
In a Danny Phantom fanfiction where Sam gets hurt, Danny might go into a rage. He'd use his ghost powers to find out who was responsible and protect her at all costs. Maybe he'd have to face a new, more powerful ghost that targeted Sam because of her connection to Danny.
One common theme is the struggle of recovery. Danny has to deal with physical and emotional pain as he tries to heal from his severe injuries. Another theme could be the importance of friendship. His friends might come together to help him, showing that their bond is strong.
No, it's not a very common genre. Danny Phantom is mainly associated with its original themes of ghost - fighting and high - school - aged superheroics. School shooting fanfiction is a very dark and serious topic, and it doesn't really fit the more light - hearted or action - adventure feel of the typical Danny Phantom story.
One possible reason could be that Maddie discovers Danny's secret identity and realizes she has been wrong about him all along. So, she decides to help him out of guilt.
One popular Danny Phantom hurt fanfiction could be 'Shadows of Pain'. It delves deep into Danny's emotional turmoil after a particularly difficult ghost encounter that leaves him physically and mentally scarred. The author does a great job of portraying his internal struggle as he tries to hide his pain from his friends and family.
One plot idea could be that Danny Phantom is in Gotham City for some reason, maybe chasing a powerful ghost that has escaped into Batman's territory. He gets hurt during a fight with some of Gotham's villains who mistake him for a threat. Batman, being the detective he is, quickly figures out that Danny is not an ordinary 'meta' but a half - ghost. He helps Danny by providing him with a safe place to recover and using his resources to track down the ghost. Another idea is that Danny is hurt by a government agency that is trying to study his unique physiology. Batman steps in, using his influence to stop the agency from further harming Danny and helps him find a way to get back home to Amity Park.