One interesting plot twist would be if the magic in Wonderland is actually a form of lost Fairy Tail magic. And the characters have to figure out how to use it to get back home. Also, what if the Cheshire Cat is an ancient Fairy Tail spirit that got trapped in Wonderland? It would change the whole dynamic between the characters and the Wonderland environment. There could be a lot of mystery and discovery involved in such a plot twist in the fanfiction.
A great plot twist could be that Alice is actually a long - lost Fairy Tail mage. Maybe she was sent to Wonderland as a child and lost her memories. Another one is that the Queen of Hearts in Wonderland is being controlled by a dark mage from Fairy Tail's world. It would turn the whole story on its head.
Another plot twist might be that the villains in the Fairy Tail world are the ones who summoned Godzilla, but they lose control of it. Now the Fairy Tail guild has to figure out a way to stop Godzilla while also dealing with the villains who caused the mess in the first place. It adds a layer of complexity to the story.
One interesting plot twist could be that the Red Queen is actually being controlled by an unseen force. It adds a new layer of mystery to her actions.
A great plot twist would be if the Fairy Tail guild members were transported to the Naruto world and had to adapt to ninja life. Or perhaps a character from Naruto, like Sasuke, gets corrupted by the dark magic in the Fairy Tail world. It would create a whole new dynamic as the other characters try to save him. Also, what if there was a prophecy in both worlds that the only way to save them was for a Fairy Tail wizard and a Naruto ninja to sacrifice themselves? That would be a very intense plot twist.
Well, perhaps a great plot twist is that Naruto's immortality is actually a curse in the Fairy Tail universe. The magic there has a different set of rules, and his inability to die disrupts the natural balance. This could lead to him being hunted not just by villains but also by some of the more morally strict magic guilds. Also, imagine if Naruto discovers that his past enemies in the Naruto world are somehow connected to an ancient evil in the Fairy Tail world, and he has to fight them again in this new context.
One interesting plot twist could be Sakura having to adapt to Fairy Tail's magic system. Maybe she discovers a new form of her own chakra-based abilities that interact with Fairy Tail magic in unexpected ways. For example, her healing jutsu could combine with Fairy Tail's healing magic to create a super - healing spell.
One interesting plot twist could be when the magic from Fairy Tail interacts with the sins' powers in Nanatsu no Taizai. For example, if Natsu's fire magic somehow combines with Meliodas' full counter, creating a new and unexpected power. Another could be the characters being transported to the opposite universe and having to adapt. Like Lucy ending up in Britannia and having to deal with the Holy Knights while the Seven Deadly Sins end up in Fiore and face off against the dark guilds.
One interesting plot twist could be that some of the zombies are actually under the control of an old enemy of Fairy Tail who has resurfaced during the apocalypse. Maybe this enemy has found a way to use the zombie hordes to target Fairy Tail specifically.
One interesting plot twist could be that characters from Fairy Tail end up in the world of Legend of Zelda and they discover that their magic has a completely different effect. For example, Natsu's fire magic might interact with the magical elements in Zelda's world in a way that either helps or hinders their quest. Another could be that the Triforce has an unexpected reaction to the Fairy Tail mages' presence, perhaps granting them new powers or cursing them. A third plot twist might be that a major villain from Legend of Zelda teams up with a dark guild from Fairy Tail to take over both worlds.
Well, in some fanfictions, a plot twist might be that the Fairy Tail guild is actually an experiment by an ancient and powerful magic user. So all the members unknowingly have a special connection to a greater power. Another cool twist is when a character's magic completely changes. Like Gray who suddenly has fire magic instead of ice magic due to some dark magic curse. Also, there are fanfictions where the main villain is a doppelganger of one of the main characters, which creates a lot of confusion and interesting scenarios.
One interesting plot twist could be that Lucy discovers a hidden power within herself that is linked to End. Maybe she can control a part of End's power and use it to save the Fairy Tail guild from a great danger. For example, she might be able to use it to stop an ancient evil that is more powerful than any they've faced before.