The house staff could be underrated characters. They've been around the Hawthorne family for a long time and surely know a lot of secrets. Focusing on them could add a whole new layer of intrigue to the story.
Maybe the distant cousins of the Hawthornes. They are often in the background but could have their own interesting stories. For example, a cousin who was always overlooked but has a unique talent or knowledge that could be useful in the inheritance games.
The old family lawyer. He seems like a side character but he must know a lot about the legal aspects of the inheritance as well as some family secrets. Expanding on his character, his backstory, and his motives could be really interesting in the fanfiction.
Rhonda Kazembe is quite an underrated character. She has a lot of potential for more development. Her skills in various areas could be explored further, like how she might use her knowledge in a different way to help the society in a new situation. Maybe she could be the key to solving a mystery that the others overlook.
Tye Longshadow is often underrated. In fanfiction, he could be given a more central role. His powers are really interesting and his backstory has a lot of potential for exploration. For instance, a fanfiction could focus on his journey to fully master his shadow powers and how he overcomes his insecurities related to being different from the more well - known heroes in the team.
Winky the house - elf. She was briefly in the fourth year story but there's so much more that could be done with her. Maybe she has some secrets about the Dark Arts that she's been hiding because she's afraid of getting in trouble.
Antoine could be a great character to focus on more. In Sonic SatAM crossover fanfiction, he could have a character arc where he overcomes his cowardice in a new and unique way. Maybe in a crossover with the Archie Sonic comics universe, he could learn some new combat skills from the more battle - hardened characters there.
The servants in the castle, like Lumière and Cogsworth, could be explored more deeply. Their backstories before the curse could be interesting. For example, what were their relationships like? And how did they come to work in the castle?
There's also Grover. He's Percy's best friend, but in a lot of fanfiction, he's just there as a sidekick. He could be developed more, like showing his growth as a satyr and his role in protecting nature. And then there's Clarisse. She's a tough and strong demigod, but often overlooked. Fanfiction could explore her in - depth feelings and her own quests that are separate from Percy's.
Pettigrew. He's often just seen as the traitor, but in fanfiction, you could explore his motives more. Maybe he was forced into his actions by some dark magic or a threat from Voldemort that no one knew about.
Dende. He has great potential. In fanfiction, he could be given a more active role in the Parallel Saga. Maybe he discovers a new type of power related to the Namekian Dragon Balls that could turn the tides in battles. He's often overlooked but has a deep connection to the Dragon Ball lore.
The Genovian citizens. In fanfiction, individual citizens could be highlighted. For instance, a young Genovian girl who looks up to Mia as a role model. We could follow her journey of trying to be like Mia, and through her eyes, we can see how Mia's actions as princess impact the people of Genovia on a more personal level.
One underrated character is Prentiss. He's often just in the background in the original, but in fanfiction, he could be the hero. Maybe he discovers a hidden power within himself that helps Peter and the gang. Another is Ted. He could be given more spotlight by having his own backstory explored, like how he ended up on the ship in the first place.