Another angle could be the creative liberties taken by the author. Fanfictions often deviate from the original story to some extent. In this case, the author might have added unique plot twists, new characters related to Kaiba and Anzu, or different power dynamics that make the story stand out from the official 'Kaiba and Anzu' narrative.
Well, the story mainly focuses on the return of an old foe. Yugi and the gang are drawn into a series of events that lead them to discover more about the Dark Side of Dimensions. This includes new and powerful cards, and duels that test their skills like never before. There are also elements of mystery and a struggle to maintain balance in the world of Duel Monsters.
Perhaps there is a plot point where the relationship between Kaiba and Anzu changes in a significant way. Maybe they have to rely on each other more than they ever did before, leading to a deeper understanding of one another.
Yugi's friends like Joey, Téa, and Tristan could also be main characters. They have always been an important part of Yugi's life and the dueling story. In the epilogue, they might be involved in helping Yugi with some new challenges or they could have their own storylines related to the dueling world.
One possibility is that it delves deeper into the mysteries that were left unsolved in the movie. It could explore the origin of some of the powerful cards or the true nature of the dark forces that were hinted at. The fanfiction might also introduce new characters who are related to the existing ones, like a long - lost relative of Kaiba who has some secrets about the Millennium Items.
Obviously, Yugi and Yami are the most popular. They are the main characters and their relationship is central to the story. Writers often like to explore their bond further, whether it's in a more emotional or action - packed way.
One idea could be exploring an alternate ending where Yugi and Yami have to face a new threat in the Dark Side of Dimensions that was hidden all along. Another could be a story about their friendship growing even deeper during an adventure in that dimension. Maybe a fanfiction where they meet new characters who have unique powers and they have to team up with them to save both worlds.
There are fanfictions where Yugi and Kaiba find themselves in an alternate dimension. Yugi's kind - hearted nature and Kaiba's determination create an interesting dynamic as they try to find their way back home. They gradually learn to understand and rely on each other more than they ever thought they would.
Yugi is always an interesting character to focus on. After the events of 'Dark Side of Dimensions', he has a new level of maturity and experience. His relationship with the spirit of Atem has also changed, so exploring his thoughts and feelings about that would be great. Another interesting character could be Seto Kaiba. He's always been a complex character, and in the post - movie world, his drive for power and his rivalry with Yugi could take on new dimensions. And don't forget about the new characters introduced in the movie. They have a lot of potential for development in fanfiction.