An old wizard or sorceress who has a connection to the castle. They might have foreseen the castle's disappearance and have been trying to prevent it. Their vast knowledge and powers could be key in the fanfic, but they might also be hiding some secrets about the castle's true nature that are revealed as the story unfolds.
A group of knights could be the main characters. They are sworn to protect the castle and when it begins to disappear, they see it as their duty to figure out what's wrong and stop it. They could bring different skills like swordsmanship, tracking, and knowledge of ancient magic to the story.
Obviously, Alexis and Castle would be the main characters. Their relationship as father and daughter is central to the 'Castle' series, so in this fanfic, their dynamic would be crucial. Castle would be the one trying to find Alexis, and Alexis would be the one in the middle of whatever situation led to her disappearance.
Well, it could be about a magical curse. Maybe an evil sorcerer casts a spell on the castle and it slowly fades away. The characters then have to go on a quest to find a way to reverse the spell and bring the castle back.
Well, it could be about Alexis suddenly vanishing from Castle's life in some mysterious way. Maybe she gets involved in a top - secret case and has to go undercover, leaving Castle worried and desperate to find her.
A brave knight who was injured in battle could be a main character. He might be struggling with not only his physical wounds but also his mental state as he's used to being strong and active.
A young peasant boy with great potential could be a main character. He is chosen from his village to go to the castle for training as a knight. There could also be an old, grizzled knight as his mentor, guiding him through the tough training regime.
A brave knight could be the main character. He is strong and determined to save the castle and its people from the paralysis caused by the accident.
A young girl who is training to be in the Olympics for shooting sports could be a main character. She spends most of her time at the Castle Shooting Range, perfecting her aim and dealing with the pressure of competition. There could also be her coach, who is like a strict but loving father figure to her, constantly pushing her to do better.
The main characters could be a group of highly skilled agents. There might be a tough - as - nails leader, like Agent Smith, who is good at making quick decisions. And then there could be a tech - savvy agent, like Agent Johnson, who can hack into any system in the castle.
Well, it could be a young adventurer who stumbles upon the ruins of the castle and becomes the key to its resurrection. Maybe they have a special gift or power that is needed.
I don't know for sure as I haven't read it. But it could be the typical hero - like a brave knight or a curious adventurer. There might also be a villain, perhaps a dark sorcerer or a power - hungry noble who wants to control the castle.