Gray would probably use his ice - make magic to try and freeze Godzilla. He'd start by creating ice pillars to immobilize the monster's legs or ice walls to block its attacks. And if that didn't work, he'd get creative, maybe making ice clones to distract Godzilla while he figures out a better plan.
Erza would likely have a more serious take on it. If the fanfiction adheres to the values of Fairy Tail and portrays Natsu in a positive light that aligns with his character in the guild, she would probably approve. However, if it contains any inappropriate or un - Fairy Tail - like behavior, she would surely be against it.
It could lead to new and interesting storylines. Fanfiction often explores alternative scenarios and character developments not seen in the original.
Happy would be flying around, providing support. He could carry small items or messages between the other Fairy Tail members. And he might even try to use his fish - shaped Exceed Beam to blind Godzilla or at least annoy it a bit. Wendy could use her Sky Dragon Slayer magic to heal any of her comrades who got injured during the fight with Godzilla. She might also try to use her magic to weaken Godzilla's attacks by creating gusts of wind to blow them off course.
Lucy and Natsu's relationship could become more intense. In some fanfictions, their bond might develop into a deeper romantic connection, which would change how they interact. Gray might become more of a rival, feeling like Natsu is getting more attention in these fictional scenarios.
Natsu would be a likely candidate. He's always up for a challenge and not afraid to take on powerful opponents. He'd probably be the first to rush towards Godzilla, either to fight it or try to befriend it in his own Natsu - like way.
For action - filled fanfictions, Natsu would be super excited. He loves battles and would enjoy seeing himself in more intense fight scenes. For romance - centered ones, characters like Lucy might be more interested. She has a soft side for love stories.
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.
Well, perhaps in the fanfiction, Godzilla is a result of some dark magic experiment gone wrong in the Fairy Tail universe. The guilds have to deal with this giant creature that is causing destruction everywhere. Lucy might use her Celestial Spirits to try and hold Godzilla off while the others come up with a plan. Gray could use his ice - make magic to try and freeze parts of Godzilla to slow it down. And in the end, they find a way to reverse the dark magic and turn Godzilla back to normal or send it away.
Some MHA characters might be really intrigued. For example, Izuku would probably study the magic systems in Fairy Tail fanfiction with great enthusiasm, seeing it as a new form of 'quirks' in a way. He'd be taking notes and trying to understand how the characters use their magic powers for good.
If transported into Fairy Tail fanfiction, one would likely find themselves in a world full of magic and chaos. The first thing might be to figure out what kind of magic you possess. You could be a part of the epic battles between guilds or help in rebuilding a guild after a great war. There are so many possibilities, from falling in love with a character to becoming a feared adversary.