I'm not sure exactly as I haven't read it. But generally, it might be about villains who for some reason find themselves in a position where they have to save the world instead of their usual villainous deeds. Maybe there's a greater threat that even they can't ignore.
I'm not sure exactly as it depends on the specific novel. But it could be some well - known villain types like a powerful sorcerer who has always been seen as evil but has a change of heart. Or perhaps a group of thieves who find out they are the only ones who can stop a great catastrophe.
In this novel, perhaps the world is in a state where the usual concepts of good and evil are blurred. The villains might be forced to save the world because they are somehow implicated in the danger. For example, if the world is being destroyed by a force that was initially unleashed by them or their kind, they would need to fix it. They may also find that saving the world is the only way to redeem themselves in the eyes of society or in their own moral compass.
Since I haven't read it, I can't say for sure. But I would expect there to be some well - known villains in the story. Maybe a powerful sorcerer who has been causing chaos before but now has to use his powers for good.
It could also be a group of bandits who have discovered that the trees in the Tree Village have some valuable resources. So, they are using their own crude methods to damage the trees and try to extract those resources. Naruto and Ino would have to stop them and protect the village.
Shigaraki would likely be disgusted if the fanfic made him seem weak or less of a threat. He'd probably scratch at his neck in irritation. Dabi would be dismissive. He'd think fanfics are just a waste of time and not worthy of his attention. Toga, though, might be intrigued. If the fanfic had a lot of blood and gore in it, or if it focused on her relationships in an interesting way, she could be really into it.
Midoriya and Toga. It's an unexpected pairing because Midoriya is the symbol of hope among heroes and Toga is a rather blood - thirsty villain. But if you think about it, Toga's admiration for heroes could be a starting point. Maybe she could be redeemed or at least have a moment of self - reflection through her interactions with Midoriya.
In 'The Lord of the Rings', Frodo is a hero. He has to carry the burden of the One Ring to destroy it and defeat Sauron, the ultimate villain. Sauron is a symbol of pure evil, desiring to rule Middle - earth. Another example is in 'Harry Potter' series. Harry is the hero, facing off against Voldemort, a powerful and feared villain who wants to take over the wizarding world and eliminate non - pure - blood wizards.
It might be Mineta. Usually seen as a bit of a comical and not - so - serious character, but in the endgame, he could have a hidden power or ability that he unlocks at the crucial moment. Maybe he discovers a new way to use his quirk that completely turns the tide of the battle.