A great idea for 'Fairy Tail Zero Fanfiction' is to explore the origin of the guild's symbols and their significance. You could also look into how the guild's rules were initially formed and what led to certain rules being more important than others. Additionally, you could write about a time when the guild was on the verge of disbanding during the 'Fairy Tail Zero' period and how the members overcame those difficulties. Maybe there was a betrayal from within the guild that almost destroyed it, and the story could be about how they healed and moved forward.
One idea could be to have the characters from both series meet in a neutral magical realm. For example, Natsu from Fairy Tail and Shiki from Edens Zero could team up to fight a common enemy that threatens both of their worlds. This would create an interesting dynamic as they have different fighting styles and powers.
One idea could be that the characters from Fairy Tail and Edens Zero meet in a parallel universe. They initially have some misunderstandings due to their different worlds and magic systems. But then they realize they can work together to fight a common enemy, like a powerful dark mage who is trying to destroy both their universes.
One idea could be exploring an alternate universe where the main characters have different magic abilities. For example, Natsu could have ice - based magic instead of fire. Another idea is to focus on the backstories of the minor characters in more depth, like how they came to join Fairy Tail. A third idea would be to create a time - travel fanfiction where characters go back in time to change a significant event in the Fairy Tail world.
One idea could be exploring an alternate universe where the main characters have different magic powers. For example, Natsu could have ice - based magic instead of fire. Another idea is to focus on a backstory for a minor character, like how they came to join the guild. Maybe a story about a character's journey to find a long - lost magical artifact that has a connection to Fairy Tail's history.
You could write a Fairy Tail fanfiction centered around a character's growth. For instance, take Wendy. You could write about her journey to master new and powerful dragon - slayer magic, facing challenges that force her to grow not only in power but also in confidence and leadership skills. It could involve her going on a solo adventure to a far - off land to learn from a reclusive dragon.
You could do a time - travel fanfiction. Have a character go back in time to when the Fairy Tail guild was first founded and see how they interact with the founders. Or, write a story where the characters swap powers. So, Erza would have Lucy's celestial magic and Lucy would have to use Erza's requip magic. This would lead to a lot of comical and also challenging situations for them. Also, you could write a fanfic about the guild taking on a mission in a completely new and strange land, filled with magic they've never seen before.
One idea could be Wendy going on a solo adventure to a far - off land in the Fairy Tail universe to discover a new type of magic. She could meet unique characters and face challenges that test her skills and growth as a mage.
A Changeling could be sent on a secret mission to infiltrate Fairy Tail by an evil organization. But as they spend time with the guild, they start to have second thoughts and eventually switch sides, becoming a valuable member of Fairy Tail and using their shape - shifting abilities to help the guild in battles.
One idea could be to have the characters from Yugioh enter the Fairy Tail world and participate in their magical guilds' activities. For example, Yugi could use his Duel Monsters to help Fairy Tail in a battle against a powerful dark guild. Another idea is a crossover where the magic in Fairy Tail is combined with the power of the Millennium Items from Yugioh. Maybe a character from Fairy Tail could be possessed by an evil spirit from a Millennium Item and the Yugioh characters have to save them.
One idea could be a character with Sharingan abilities being transported into the Fairy Tail world. They could use their Sharingan to copy the magic of Fairy Tail wizards. For example, copying Natsu's Fire Dragon Slayer magic and using it in unique ways.