The plot might start with Hiccup having a strange encounter, like stumbling upon a hidden cave with a magical artifact. This artifact could be the key to his transformation into a dragon god. As he becomes more dragon - like in his powers, he could gain the ability to communicate with dragons on a whole new level, understanding their deepest thoughts and feelings. And he would surely have to use these powers to protect Berk from threats that normal human - dragon alliances couldn't handle.
Well, it could be that Hiccup is cursed by an evil sorcerer who wants to turn him into a dragon as a form of punishment. But as he turns into a dragon, he finds that he has a new connection with the dragon world. He starts to see things from a dragon's perspective and uses this to bring peace between humans and dragons in a whole new way.
Well, it could involve Issei discovering some ancient dragon magic. Maybe he stumbles upon a dragon's lair and is blessed with dragon powers. He might start to have dragon - like instincts, like a strong urge to hoard treasures or protect a certain territory.
The fanfiction could explore Peter Parker becoming a god in a more spiritual sense. Maybe he gains a connection to a higher power or energy source. He could then use this new - found divinity to heal the world, not just in a physical sense but also on an emotional and spiritual level. For example, he could heal the traumas of those affected by crime or disasters. However, this new power would also attract negative forces. Villains might team up to try and take his power away, leading to epic battles where Peter has to use his wits as well as his god - like abilities.
Well, one possibility is that Percy has to face a great war that threatens the entire world of the gods and mortals. He might start with his normal skills but as he gradually takes on the role of the God of War, he gains new powers like enhanced combat strategy and the ability to inspire great armies. Maybe he has to fight against an ancient evil that has risen again, and his new status as the God of War is the only hope to defeat it.
One possibility is that Lucy discovers a hidden power within herself that is related to dragon slaying. Maybe she has a long - lost ancestor who was a dragon slayer. This newfound power could lead her on a journey to learn more about it, facing challenges along the way, like dealing with other mages who are jealous or scared of her new abilities.
Well, it could be about Natsu's journey to becoming a Dragon God and how he attracts a harem along the way. Maybe he gains new powers that make him irresistible to certain characters.
Well, in a Naruto becomes a hollow fanfiction, perhaps the chakra system in Naruto gets corrupted and turns him into a hollow. His appearance would change to something more menacing. He might start to crave spiritual energy instead of normal food. His relationships with other characters would be on edge. For example, his bond with his teacher Kakashi would be tested as Kakashi tries to figure out how to reverse the transformation or at least help Naruto co - exist with his new hollow self.
In a Naruto - becomes - a - teacher fanfiction, Naruto could focus on teaching his students about the value of friendship and teamwork. He might organize team - building exercises that are actually dangerous ninja missions. His students would learn to rely on each other, just as he did with his own team. He could also share stories about his adventures with the Akatsuki, making sure his students understand the threats that still exist in the ninja world.
In a Naruto becomes a hermit fanfiction, he could be on a journey to find a deeper meaning to his existence. He might abandon his fame and status. Living as a hermit, he'd have to fend for himself, which would make him stronger in a different way. He could start to understand the true essence of chakra in a more spiritual sense, away from the battles and politics of the shinobi villages.
The plot could also involve Naruto being transported to the world of Sparda. There, he has to learn the ways of that world to survive. He might meet characters similar to those in his own world, but with different abilities. And he could form new alliances, like teaming up with demons who oppose the main evil forces in the Sparda universe.