It could involve Erza facing challenges in the Edolas version of Fairy Tail. Maybe she has to deal with different versions of her friends or new magical threats specific to that realm.
One idea could be exploring the backstories of the Edolas versions of the main Fairy Tail characters in more detail. For example, how did Edolas Natsu become the way he is? Another idea is to create a story where the Fairy Tail guild from Earth - land has to team up with their Edolas counterparts to fight a common, powerful enemy that threatens both worlds. Maybe a new, dark magic has emerged that only the combined strength of both guilds can combat.
One key element is the contrast between the two worlds. Edolas has its own unique magic and society, and seeing how the characters from there react to Fairy Tail's more chaotic and emotional world is really interesting.
Well, aside from the obvious ones like Natsu, Lucy, Gray, and Erza, there could also be some supporting characters from the original Fairy Tail story that become more prominent in this 'Back to Edolas' fanfiction. For example, Happy, Natsu's exceed companion, might play an important role. Maybe Wendy Marvell could also be involved, with her healing and sky - dragon slayer magic. And of course, characters like Makarov, the guild master, might also have a part to play in the events that unfold in Edolas.
Erza is also frequently paired with Edolas Lucy. Erza's strong leadership and sense of justice can influence Edolas Lucy in many ways. And the relationship can be developed in different directions, such as a mentorship kind of relationship or a deep friendship where they support each other through various challenges in the fan - created stories.
Well, obviously, the two Grays are the main characters. One is Gray from the regular world we know, and the other is Gray from Edolas. Their encounter and the events that unfold around it are likely to be the central focus of the fanfiction.
First, do some research on the existing Fairy Tail Edolas arc. Understand the characters, the setting, and the rules of magic in that world. Then, come up with a unique concept or plot. It could be a simple idea like 'What if a minor Edolas character became a hero?' or something more complex. Next, create an outline of your story. Decide on the beginning, middle, and end. Start with an engaging opening, like a mysterious event in Edolas that draws the characters in.
One interesting concept could be exploring how Lucy from Edolas adapts to the Fairy Tail world. Maybe she has different magical abilities or a unique perspective on friendship compared to the original Lucy.
The fanfiction could also focus on the character development of Gray. Meeting his counterpart from another world might make him question his own identity and purpose. This could lead to him growing in new ways, perhaps becoming more confident or learning new magic techniques from the Edolas Gray.