The titanium dragon slayer could be cursed. Every time they attempt to slay a dragon, they are instead inflicted with a part of the dragon's power, slowly turning them into a half - dragon, half - slayer hybrid. This transformation makes them an outcast among their own kind and forces them to reevaluate their role in the world of dragon slaying.
Maybe Gray has to team up with a dragon in order to defeat an ancient evil that threatens to destroy the world. The dragon could have its own motives and Gray has to figure out if he can trust it.
One idea could be that the poison dragon slayer has to overcome a rare and powerful poison - based curse that is slowly sapping their strength. They must find a mythical antidote hidden in an ancient dragon's lair.
Well, a possible plot could involve Lucy going on a journey to find the origin of ice dragon slaying magic. Along the way, she meets other dragon slayers who are skeptical of her because she's not a typical dragon slayer. But she proves herself by using her unique skills and knowledge related to ice dragons. She might also uncover a dark secret about the history of ice dragon slaying that changes her perspective on it all.
One idea could be Juvia discovers a new water - based magic that only water dragon slayers can use. It gives her the ability to transform water into different forms, like crystal - like structures for defense. Another could be a time - travel plot where Juvia goes back in time and meets the first water dragon slayer and learns ancient techniques from them. And a third idea is that Juvia has to team up with other dragon slayers to defeat a powerful water - based villain who is misusing water magic and causing chaos.
Well, one idea could be the fusion of Naruto's ninja skills with crystal dragon slaying magic. Maybe Naruto discovers a hidden power within him that allows him to summon crystal dragons and use their powers in battles against powerful foes in the Naruto universe.
Well, a cool plot might involve Natsu being transported to a parallel world where he is the only water dragon slayer. He has to adapt quickly to this new role and use his skills to fight against an evil force that is draining the water from that world. Also, he could meet alternate versions of his friends and have to convince them to trust him, since his powers are so different from what they know.
Maybe the Wood Dragon Slayer has a connection to the Sage of Six Paths. This connection gives them unique abilities that no one else has. They could discover this connection during a dangerous mission in an ancient ruin. And then they have to learn how to control these newfound powers while also dealing with the political unrest in the village that arises from others fearing their new strength.
Maybe the fanfiction could focus on a rivalry between two dragon slayers, one with mountain dragon slayer magic and the other with a different type. They compete to see who can slay the most powerful dragon, but in the end, they have to team up to face a common threat that is endangering the entire dragon slayer community. The unique powers of the mountain dragon slayer magic could be the key to victory.
One idea could be that Naruto discovers he has the power to slay golden dragons during a mysterious mission in a hidden land. Maybe the dragons are guarding an ancient power that could change the ninja world.
One idea could be that Lucy discovers a new, rare form of dragon slaying magic. Maybe she finds a hidden dragon lair where this magic is stored and has to overcome various traps and challenges to obtain it.