They might be quite surprised. Some characters could find it interesting to see how fans interpret their lives and actions. For example, Jim might be amused or flattered to see the different adventures fans create for him in the fanfiction.
Some popular ones include those that are recreations of key scenes from the show with added twists from the fanfiction. For example, there are videos that might show an alternate ending to a particular Trollhunters arc. You can search for 'top Trollhunters fanfiction on YouTube' and look at the videos with the most views and positive ratings.
If you're looking for a place to engage with Trollhunters fanfiction, Fanfiction.net could also be an option. It has been around for a long time and has a decent amount of Trollhunters - related stories. Just be aware that the interface might not be as modern as AO3, but it still has a lot to offer in terms of content.
In addition to them, there are some other significant characters. For instance, Strickler, who has his own motives and secrets. He is a complex character who sometimes helps and sometimes causes trouble for the Trollhunters. And there are various troll characters with different personalities and abilities, each playing a role in the story's development, like Draal, a powerful troll who also has an important relationship with Jim.
Jim Lake Jr. from Trollhunters would be an obvious choice as he is the main Trollhunter. He could bring his knowledge of the troll world and his fighting skills to the crossover. Also, Aja from '3 Below' would be great. Her spunky personality and her alien powers would add a lot of fun and action to the story.
If it's a crossover with the Legend of Korra, Korra herself would be an excellent addition. She is a powerful bender and has a lot of experience in fighting evil. She and the Trollhunter could learn from each other's fighting styles. Asami could also be included, providing her engineering skills to help the Trollhunter with any technological needs in their battles against the common foes.
Well, I think Aja is really popular. She has this great energy and her alien powers are really cool. Writers can focus on her relationships, like her friendship with the humans or her bond with Krel. Krel is also a top pick. His inventions and his role as the tech - savvy one in the group can be the center of many stories. Also, Varvatos Vex is a character that many like to write about. His loyalty and his warrior - like nature can add a lot of action and drama to a fanfiction.
In the 'trollhunters origin story', Jim Lake Jr. is a key figure. He is an ordinary kid who gets thrust into this extraordinary role of trollhunter. Blinky, a wise troll, is also very important. He guides Jim through the ins and outs of the troll world. Additionally, there may be other trolls like AAARRRGGHH!!! who might also be part of the origin story, especially in relation to the early battles and the establishment of the trollhunter's purpose.
Jim Lake Jr. from Trollhunters is an obvious choice. His journey as a Trollhunter and his growth throughout the series make him a very dynamic character. In a crossover, seeing him interact with the characters from 3Below, especially with his sense of justice, would be really interesting. Another interesting character would be Aja from 3Below. She is a strong - willed princess who has her own set of skills and knowledge. Her leadership skills and her ability to adapt to new situations could create some great storylines when paired with the Trollhunters.