I think Adam and his future self are essential characters. Their interactions can create a lot of interesting dynamics. Then there's the character of Laura, Adam's love interest. Her presence can add an emotional aspect to the fanfiction. Also, including some of the military personnel from the movie, like the commander, could bring in elements of authority and conflict.
Well, Adam is the central character, so he has to be there. But also, it would be cool to include some new characters. For example, a time - traveling rogue who initially seems like an enemy but later becomes an ally. And the character of Adam's father, who is only briefly mentioned in the movie, could be explored more. You could also include some characters from different time periods that Adam encounters during his travels, like a group of prehistoric humans or a futuristic alien species, which would make the fanfiction really unique.
Obviously, Adam himself is a must - include. His character has a lot of depth and potential for further development. Also, his mother would be great to include as she plays an important role in the story. And the villain from the movie could be brought back in a new and more menacing way.
Billy Abbott could be an interesting addition. He could bring some outside drama, perhaps through a business deal or some personal vendetta against Adam. His flamboyant personality would contrast with Adam and Chelsea's relationship and add an element of chaos to the fanfiction.
The enchanted objects in the castle like Lumière and Cogsworth would be great. They add humor and charm to the story. Also, Gaston could be included in a different way, like he has a change of heart and tries to help them. And Belle's father could also be a key character, perhaps he discovers something important about the curse.
Ace is a great character to include. He was Whitebeard's adopted son, and their relationship was very deep. Stories about their interactions, whether it was Ace learning from Whitebeard or them having father - son moments, are always interesting. Marco is also a good choice. As Whitebeard's right - hand man, he could be in stories that show the inner workings of Whitebeard's crew and how they strategize and operate. Another one could be Luffy. Since Luffy had a connection with Ace and later respected Whitebeard, a fanfiction could explore their interactions.
Obviously, Bahubali himself is a must - include. His strength, courage, and leadership make him a central figure. Then there's Kattappa. His loyalty and his complex relationship with Bahubali can add a lot of depth to the story. Also, Devasena is an important character. Her love for Bahubali and her own strength as a princess can bring in elements of romance and female empowerment in the fanfiction.
The Warrens could be great characters to include. Their knowledge of the occult and their experience with haunted objects like Annabelle can add a lot of depth to the story. They can be the ones trying to either save Annabelle or stop her from causing more harm.
Obviously Chowder himself is a must - include. Mung Daal, as his mentor, also makes for great content. And Truffles, with her strict but caring nature, can add interesting dynamics to the story.
Charlie would be a great character to pair with Adam. Charlie is all about redemption and Adam could either be a foil to her or be influenced by her positive attitude. Their interactions could be really interesting as they have different outlooks on the whole idea of sin and redemption in the Hazbin Hotel world.
In my Adam Project fanfic, Adam is stranded in an alternate timeline where his younger self doesn't believe in time travel. Adam has to convince his younger self not just with facts but with the power of their shared memories. He takes his younger self to the place where they used to play as kids. It's an old abandoned building that now has a different look in this timeline. Adam starts telling stories of their adventures there, and slowly, the younger Adam begins to remember. This helps them bond and also makes the younger Adam more open to the idea of time travel and helping Adam fix the timeline.
For a more unique take, including Jiraiya could be great. His pervy but knowledgeable personality could lead to some humorous and yet useful moments. He might have some ancient knowledge about the connection between the Naruto world and the Pokémon world where Darkrai comes from. On the Pokémon side, Cynthia could be a great addition. As one of the strongest Pokémon trainers, she could offer a different perspective on Darkrai and also help in battles against any enemies that might be using Darkrai's power for evil.
Obviously, the clone troopers themselves are essential. Characters like Rex, Cody, and Fives are very popular. Jedi generals like Anakin Skywalker and Obi - Wan Kenobi also make great additions as they often lead the clone troopers into battle. Then there are the villains. General Grievous can be a great antagonist in a Clone Trooper fanfiction as he is a fearsome enemy who the clones often face.