Perhaps a group of students accidentally time - travel while working on a new dueling experiment. They end up in a parallel GX universe where the roles of the characters are reversed. They have to figure out how to get back while also dealing with the different versions of their friends and enemies in this strange new world.
Another plot could involve a time-traveling duel. A powerful duelist from the future uses time-travel technology to come back to the GX era to challenge Jaden. The duels would have new rules and cards from the future, making it a very exciting and different kind of duel for Jaden and his friends to face.
To write compelling characters in Yugioh GX time - travel fanfiction, you need to consider their relationships. A character might have a complicated relationship with a past version of someone they know. For instance, if a character's past self was a bully, the present - day character has to deal with that when they meet their younger self. Also, their growth throughout the time - travel journey is important. They should learn from their experiences in the different time periods.
One idea could be a character from the future traveling back to the early days of the Academia. They could try to change the course of events that led to the war and destruction in their time. Maybe they have some hidden knowledge about a powerful card that was misused and they want to prevent that from happening.
Perhaps a crossover with a superhero universe. The Yu - Gi - Oh GX characters gain superpowers related to their cards. For instance, a character who uses a fire - based monster card now has the ability to control fire in real life. They team up with the superheroes to fight a common enemy, and there are duels integrated into the battles where the outcome affects the overall fight in the superhero world.
One idea could be that Naruto is transported to the world of Yugioh GX and has to learn the rules of Duel Monsters to survive. He might use his ninja skills in unique ways during duels, like using shadow clones to confuse opponents.
Another possibility is that the kidnappers are after Alexis because of her family's influence in the dueling world. They could be trying to use her as a bargaining chip to get access to some rare and powerful duel cards. Her brother Atticus might also get involved and use his own resources outside of the academy to try and rescue her.
A cool plot could be time traveling to a point where a powerful and lost duel monster card was created. The character has to face challenges and duel against ancient duelists to obtain the card. This card then becomes a key factor in a major tournament in their own time. Or, they travel to a time when the Zexal powers were first discovered and get involved in the events that led to their development, changing the course of history in the process.
One idea could be that a maiden character in the Yugioh GX world falls in love with a duelist. She could start attending his duels, secretly cheering him on and trying to find ways to get closer to him. Maybe she offers him good - luck charms before his big matches. Another plot could involve the maiden being from a rival school and falling in love with a Yugioh GX student, which creates a conflict of loyalty.
One common theme is the clash of different dueling styles. Since Yugioh and GX have their own unique styles, in crossovers, seeing how they interact is often explored.
One idea could be that Jaden's friends from different dueling academies come together to form a sort of study group. Along the way, they all develop a deep friendship with Jaden that could be seen as the start of a harem - like situation. They support each other in duels and grow as duelists together.
Aster could get hurt in a training accident in a fanfic. He might be trying out a new and dangerous dueling technique. Since he's always pushing himself to be better, he overestimates his abilities and ends up with a minor injury like a sprained wrist. This could then lead to a sub - plot where he has to learn patience and the importance of proper training.