To handle the damage in How to Train Your Dragon fanfiction, you could look at the resources available to the characters. Maybe they have special tools or allies who can help. Also, think about how the damage affects the plot and character development.
One way is to introduce a special cure or remedy that Hiccup discovers during his adventures. You can also explore how his friends and allies support him through this difficult time.
You could focus on showing his gradual change through significant events or interactions with other characters.
Well, you could try calming Toothless down with treats or gentle strokes. Maybe find out what's bothering him and solve that issue.
One way could be for Hiccup to seek the help of other dragon riders or wise elders who might have knowledge about breaking the curse.
Well, you could have the story focus on how Astrid's illness brings the group closer together as they work to help her recover. Or maybe it leads to a discovery of a hidden power or solution within the dragon world.
One way could be to introduce a magical cure or an event that breaks the brainwashing. Maybe a key moment from Hiccup's past triggers his return to normal. Also, the support of his dragon could play a crucial role in restoring his mind.
You might make the illness a metaphor for a larger challenge Hiccup needs to overcome within himself. It could lead to personal growth and a deeper understanding of his role in the dragon world.
You could have other characters try to wake him up with various methods, like using magic or seeking help from a wise elder.
One way could be to have him get some much-needed rest and recovery time. Maybe he takes a nap or spends a day doing nothing but relaxing.
Maybe Hiccup could learn some self-defense skills and stand up for himself. Or, he could find an adult he trusts to help him solve the problem. It all depends on how the story unfolds and what kind of tone you want to set.