Perhaps Jaden leaves Duel Academy due to some sort of inner turmoil. He could be haunted by his experiences with the Shadow Realm or other dark forces. He decides that leaving the academy is the best way to find peace and figure out who he really is without the constant pressure of dueling for grades and reputation. He might travel to remote places, meet new people, and learn different dueling styles that help him on his path to self - discovery.
A major plot twist could be that Jaden's departure was actually a ruse. He was secretly working with an unknown organization to expose a hidden threat within the Duel Academy. He pretends to leave, but then sneaks back in to gather evidence. This would turn the whole 'leaving' concept on its head and add an element of mystery and intrigue to the fanfiction.
It's really hard to say. Jaden has his own set of powerful cards and his unique dueling style which is quite aggressive and adaptable. However, Yugi has a lot of experience and his strategies are very deep. So it could go either way depending on how the duel is set up.
Well, he might introduce his unique ninja skills to the Duel Academy. Maybe he'll use his shadow clone jutsu during duels, confusing his opponents. He could also make friends with some of the students there who are interested in his different fighting style.
Well, he might introduce some new spells from the wizarding world of Hogwarts. For example, the Patronus charm could be a game - changer in duels at Duel Academy. His knowledge of Defense Against the Dark Arts would give him an edge in battles.
It could be a rogue teacher at Duel Academy who has his own dark motives. He might be secretly researching dangerous dueling techniques and using students as guinea pigs for his experiments.
In this fanfiction, Mokuba running off to Duel Academy could lead to him getting involved in a mystery. There could be a secret group at the academy that he stumbles upon. He might have to use his wits and dueling skills to uncover what they're up to. And who knows, he could even find a rare card along the way.
Naruto's teaching style at Duel Academy would likely be energetic and motivational. He'd probably share his own experiences of growing up, facing challenges, and never giving up. His ninja training could also translate into teaching students discipline and perseverance in dueling.
Jack Atlas is often a popular choice. His confident and somewhat arrogant personality makes for great character development in fanfiction. Writers can explore his backstory more deeply and how he interacts with the Duel Academy environment.