Maybe a plot where the pregnant Fairy Tail girls have to face a new threat to the guild while dealing with their pregnancies. They could use their newfound maternal instincts to protect the guild in unique ways.
Well, perhaps a plot could revolve around Gale's pregnancy being a source of new-found strength. Maybe there are magical elements related to the pregnancy that give her special abilities or insights. Also, it could be interesting to see how Gale and her partner deal with the unexpected reactions from their enemies who might try to take advantage of her condition.
A possible plot could be that Gajeel and Levy go on a journey to find a special place to raise their child. Along the way, they encounter old enemies who now see the pregnant Levy as an easy target. But they fight together, with Gajeel being extra protective. Also, they could have different ideas about parenting. Levy might want a more studious and peaceful upbringing for the baby, while Gajeel wants to train the baby to be tough from a young age. They then have to find a middle ground.
One idea could be that Levy discovers she's pregnant during a big guild mission. This could add a whole new layer of tension as Gajeel becomes overly protective. Maybe they have to face an enemy who specifically targets Levy because of her pregnancy. Another plot could involve Levy struggling with the changes in her body and magic while pregnant, and Gajeel having to learn how to support her in ways he never thought possible.
One idea could be exploring how the other members of Fairy Tail support Lucy during her pregnancy. For example, Natsu might be overprotective, always making sure she's safe on missions or just in general. Another could be Lucy writing in her diary about her hopes and fears for the future as a mother, while also reflecting on her adventures in Fairy Tail.
One idea could be a new character arriving at Fairy Hills and having to adapt to the unique living situation. They could face challenges like getting along with the different personalities of the Fairy Tail mages living there.
One plot idea could be how Lucy adjusts to her new state while still being part of the Fairy Tail guild. Maybe she has to take on less dangerous missions at first and her friends rally around to protect her. For example, Natsu could be overly protective, getting into comical situations as he tries to keep her out of harm's way.
Perhaps there's a dark secret hidden in the academy's history. A group of students accidentally stumbles upon it and has to work together to either keep it buried or expose it, depending on what they find out. Along the way, they face many obstacles and learn more about themselves and their magic.
A cool plot could be that a powerful artifact in Skyrim is causing chaos and the Fairy Tail members are summoned to find and secure it. Along the way, they meet up with the Dragonborn. Some members might befriend the Dragonborn and help in their battles, while others might be a bit more skeptical and think the Dragonborn is a threat to their own power within the group.
One idea could be that Ichigo arrives in the Fairy Tail world and his powerful spiritual energy is mistaken for a new type of magic. He could join forces with Natsu and the gang to fight against a common enemy that threatens both his world and the Fairy Tail world. Another could be that Ichigo's zanpakuto has some sort of unique interaction with the Fairy Tail magic, like being able to absorb or nullify certain spells.
One idea could be a story where a character from Fairy Tail is injured and ends up in a hospital in a foreign land. They meet a mysterious healer there who has a connection to an ancient Fairy Tail magic. Another could be that the hospital is actually a front for an evil organization that is stealing the magic of Fairy Tail members who come for treatment. Or perhaps a Fairy Tail mage has to use their magic in creative ways to heal the sick in a hospital that's short on supplies.