Fluttershy could also be included. Imagine a scenario where Trixie is trying to put on a big, bold magic show and Fluttershy's timidness contrasts with that. Twilight might be caught in the middle, trying to make sure Fluttershy doesn't get too scared and that Trixie doesn't feel like her show is being ruined.
Rainbow Dash is another excellent choice. If there's a race or a challenge that involves magic and speed, Rainbow Dash's competitive spirit could drive the story forward. She could also be the one who challenges Trixie and Twilight to prove their magic skills in a more physical or action - based way.
Jacob could be a great addition. He has a complex relationship with Bella in the original series. In fanfiction, his interactions with Charlie could be explored further. For example, how Charlie reacts to Jacob's wolf - shape - shifting abilities and his love for Bella.
Goten would be a great addition. He could add some light - hearted moments and also show the family dynamic between him, Gohan and Chichi. His innocent and sometimes mischievous nature would contrast well with Gohan's more serious side.
One idea could be that Trixie and Twilight Sparkle team up to solve a mystery in Equestria. Maybe a powerful magical artifact has gone missing and their combined knowledge of magic is needed to find it.
Snowball is a great character to include. He adds an extra layer of conflict as he also has his own ambitions for world domination. Another good one could be the lab scientists. Their presence can add some mystery and backstory to Pinky and the Brain's situation. And Elmyra, she can bring chaos as she always does in the original show, disrupting Pinky and the Brain's carefully laid plans.
Annabeth could be a great addition. She could bring her strategic mind to help Percy deal with Medusa. For instance, she might come up with a plan to use Medusa's own pride against her.
A common theme is friendship. Since Twilight and Trixie are both from the same universe, many fanfictions explore how they can become friends despite their differences. Another theme is magic. Given that they are both magic - users, stories often revolve around their magic skills and how they can learn from each other. Redemption is also a theme, especially for Trixie who has had some not - so - great moments in the original series.
They usually have a lot of magical adventures and fun interactions between the two characters. The art style can be quite colorful and detailed.
Gary Oak could be an interesting addition. His rivalry with Ash is well - known, and his skills as a Pokemon trainer would make him a valuable character. Then there's Blue, who has a connection to Red. His different approach to Pokemon training compared to Ash and Red could create some interesting storylines. And don't forget about Professor Oak. He could provide guidance and knowledge to both Ash and Red, and his presence always adds a sense of wisdom to the Pokemon world.
Well, Dr. Wells could be an important character. He might have some knowledge or secrets that are relevant to the story of Barry and Caitlin. His presence could add a sense of mystery and also some conflict. Another option is Killer Frost. If Caitlin is struggling with her alter - ego, it could be a major plot point and Killer Frost could interact with Barry in unique ways.
Fukuzawa, the president of the Armed Detective Agency, would be a good character to include. His leadership and wisdom can influence the events involving Soukoku. Higuchi, who is loyal to Akutagawa, can also be added. Her interactions with Soukoku can be used to explore the power dynamics within the Port Mafia. And Elise, Mori's ability manifestation, can add an element of mystery and unpredictability to the fanfic.