I really like 'The Time Traveling Lich'. In this fanfiction, the Lich uses time travel to try and rewrite history in his favor. It's full of action and has some really interesting twists on the characters' relationships. It shows how time travel could completely change the power dynamics in the Adventure Time universe.
Archive of Our Own (AO3) is another great place. It has a well - organized tagging system. So when you search for Adventure Time fanfiction with time travel, you can easily filter through different ratings, pairings, and other aspects to find exactly what you're looking for.
Gohan could also time - travel to a point in Saiyan history. He might witness the destruction of Planet Vegeta and try to save some of the Saiyans. This would completely change the course of the Saiyan race and his own story. He'd have to deal with the cultural differences and the power - hungry nature of some of the Saiyans he saves.
Hermione's inquisitive and studious nature would mean she'd be constantly seeking knowledge during the time - travel. She'd be taking notes, asking questions, and trying to understand the historical context. For example, if they went back to the time of the Goblin Rebellions, she'd want to know all about the reasons behind it. Bill, on the other hand, being more laid - back yet brave, would be the one to jump into action when danger arises, like if they were discovered in a time they shouldn't be.
Rose Granger - Weasley could also be a sidekick. She is intelligent like her mother Hermione. In a time - travel scenario, say when they go back to the Goblet of Fire times, she could use her smarts to figure out the complex magical rules and traps. Scorpius, with his knowledge of how things are supposed to turn out, could work with her to change the outcome for the better, like preventing some of the more dangerous tasks from being so deadly.
Robin, being more reserved and knowledge - seeking, would approach the time travel with a more cautious and inquisitive mindset. She would be interested in learning about the history and culture of the different eras. Her calm nature could balance out Luffy's impulsiveness. For instance, when Luffy wants to rush into a dangerous place, Robin might stop him and suggest they gather more information first.
In a time - travel scenario to the Clone Wars, Anakin could be a natural ally. He and Ahsoka have a strong bond, and he would likely believe her if she told him about time travel. Together, they could face any challenges.
One great Adventure Time time travel fanfic is 'Time Twisted Tales'. It takes Finn and Jake on a wild journey through different timelines, where they meet alternate versions of their friends. It has really cool art and a fast - paced plot that keeps you hooked from start to finish.
Koriand'r, her mother, could also be an ally. Her alien powers and knowledge of different cultures and technologies across the universe could come in handy. She might be able to use her powers to manipulate energy in ways that help with the time travel process or protect Mar'i in a dangerous time period.
Percy is impulsive. So in time travel, he might rush into situations without fully thinking about the consequences. For example, he could see a monster from Greek mythology in a different time period and immediately attack it, not realizing that this action could change the future. Artemis, on the other hand, is more calculating. She would likely try to analyze the situation first, like figuring out how the time period they are in affects the monster's behavior and power.