In a fanfiction, Batman could be injured in a city - wide disaster that he tries to prevent. He gets caught in the rubble and is severely injured. This forces him to train a young protege more intensively to take over some of his duties while he heals. The story could focus on their relationship and how the protege grows in Batman's absence.
Perhaps Batman is injured in a trap set by the Joker. While he's injured, the other villains in Arkham Asylum sense his weakness and start planning a mass breakout. Batman has to use his wits and the help of Oracle to stop them from the confines of his Batcave, all while nursing his injuries.
In a fanfiction, Robin could be injured in a trap set by an old enemy of Batman. This enemy specifically targeted Robin to get back at Batman. Batman, upon finding Robin injured, is consumed with guilt and anger. He goes on a full - scale investigation to find the enemy. Meanwhile, Robin is in a critical condition and Alfred has to use all his medical knowledge to keep Robin alive. The story could focus on Batman's internal struggle between his need for revenge and his responsibility to Robin, and how he overcomes this to save both Robin and Gotham.
One idea could be that Batman gets injured during a fight with a new super - villain. A young fan witnesses this and decides to step up and help in his own way. Maybe he uses his knowledge of technology to create something that aids Batman's recovery or gives him an edge in the next encounter.
A plot idea could be that Nightwing is injured while saving a group of hostages. Batman then has to deal with the criminals who were holding the hostages as well as take care of Nightwing. The story could explore Batman's feelings of guilt for not being there in time to prevent Nightwing's injury.
A plot idea could be that Batman is injured by a kryptonite - enhanced weapon during a fight against a Lex Luthor - controlled Superman in the Justice League. His injury makes the other members realize how vulnerable they are without Batman's strategic mind. So they have to find a way to heal him quickly while also preventing Luthor from causing more chaos.
Loki could be injured while exploring a dangerous new realm. He's attacked by strange creatures and sustains a life - threatening injury. His journey to recover could involve him having to rely on a local healer who has a very different view of magic from his own. This forces him to adapt and learn new ways to heal.
One plot idea could be that Spider Man gets injured during a fight with a new super - villain. As he's injured, he has to rely on his friends and the citizens of New York to help him hide from the villain's minions while he recovers. Maybe Mary Jane finds him and nurses him back to health in a secret location.
One plot idea could be that George's OC is injured during a magical battle. The friends around the OC then have to figure out how to heal the OC using rare potions and spells. Another could be that the OC is injured in a sports event organized in a fictional world, and George has to deal with the guilt of not being able to protect the OC. A third idea is that the OC gets injured while exploring an ancient, dangerous ruin and the story follows their journey of recovery while uncovering secrets of the ruin.
One idea could be exploring what if Bruce Wayne's identity as Batman was exposed accidentally by a new high - tech surveillance system in Gotham. Another could be a story where Batman has to take on a new identity temporarily to infiltrate a secret criminal organization that has been studying his every move as Batman.
Perhaps they could start off as rivals in the fanfiction. Batman from the present is skeptical of Batman Beyond's more high - tech approach. But as the story progresses, they learn from each other and become a great team. For example, Batman could teach Batman Beyond some of his old - school detective skills, while Batman Beyond shows Batman new ways to use technology in combat and surveillance.
She could be injured by a new type of dragon that no one has seen before. This would lead to a story where the riders have to study this dragon to find a way to cure Astrid. For example, they might discover that the dragon's venom has a unique antidote that can only be found in a certain part of the archipelago. Hiccup would be desperate to find it and in the process, learn more about the new dragon and its behavior.