Who could be the main antagonist in a 'natsu becomes a fire dragon' fanfiction?

It could be an evil dragon slayer who is jealous of Natsu's new form. This antagonist might try to steal Natsu's power or find a way to turn him back to his normal self out of envy.

Maybe an ancient dragon that has been awakened from its slumber and views Natsu as an intruder in the dragon world. Since Natsu is a new - made dragon, this old dragon might try to drive him out or even harm him.

Another option is a rival dragon slayer who sees Natsu's transformation as a threat to his own status. This rival could try to stop Natsu from fully becoming a dragon or try to defeat him to prove his own superiority.

A powerful dark dragon slayer who has mastered both shadow and ice magic could be a great antagonist. He could be jealous of Natsu's natural ability with fire and his popularity among the guild, and thus wants to prove his superiority.

It could be an old and powerful vampire lord who sees Natsu as a threat to his rule. Since Natsu is a new and different kind of vampire, the lord might want to eliminate him.

One possible plot could be that Natsu is cursed by a dark wizard. This curse slowly transforms him into a fire dragon. As he changes, he struggles to control his new dragon - like instincts and powers. His friends initially fear him but then realize they need to help him break the curse.

Well, perhaps the plot could involve Natsu's transformation being a result of some powerful magic or a dark curse. He might struggle to control his new dragon form at first, causing chaos among his friends and allies.

It could be a dark wizard who wants to capture Hedwig - as - a - dragon for her powerful new form. Maybe he wants to use her dragon abilities for his own evil plans.

The main antagonist could be an evil knight who has a vendetta against dragons. When the princess turns into a dragon, he sees her as a prime target and tries to slay her, believing all dragons are evil. He doesn't care that the princess was once human and is only focused on his own prejudiced views.

There might be a group of anti - magic fanatics as the main antagonists. They view Natsu's new and extremely powerful magic as a danger to the natural order of the magical world. They would try to eliminate Natsu and any other powerful mages in Fairy Tail who support him, believing that magic should be limited and controlled, not allowed to reach such overpowered levels as Natsu has.