What could be the plot in a 'Zeref kidnaps Natsu' fanfiction?

Gray would probably be one of the first to want to go after Natsu. He and Natsu have a long - standing rivalry but also a deep friendship. He'd be furious and determined to rescue Natsu. Lucy would be very worried too. She might use her celestial spirit magic to try and find Natsu's location. Erza would be very focused and strategic, rallying the rest of Fairy Tail to come up with a rescue plan.

Well, it depends on the specific fanfiction. Some might have a plot centered around their unique friendship in a different AU (alternate universe), like they team up to fight a common enemy. Others could explore their relationship in a more emotional way, perhaps with Zeref having to deal with her new female form and Natsu being there to support her in ways different from the original story.

One idea could be that baby Natsu has some sort of special connection to Zeref that even Zeref doesn't fully understand at first. Maybe Natsu's presence starts to change Zeref's dark thoughts a bit.

It could be another dark mage who sees the potential in baby Natsu and wants to use him for evil purposes. This mage might view Zeref as an obstacle in getting to Natsu.

If Natsu and Zeref join Fairy Tail in fanfiction, it would change the dynamic of the guild completely. The other members would have mixed reactions. Some might be distrustful of Zeref due to his past actions. However, as time passes, they could see the good in him. Natsu and Zeref together could attract a lot of attention from outside forces. Enemies might target Fairy Tail more because of their combined power. But also, they could inspire the guild to become even stronger, with everyone striving to keep up with their new powerful comrades.

One plot idea could be that Zeref discovers a way to reverse his curse through Natsu. Since Natsu is his creation, there might be some hidden connection that could be explored. Maybe Zeref tries to use Natsu's unique dragon - slayer magic to break the chains of his dark magic.

A lot of these fanfictions also have a theme of redemption. Fem Zeref might be portrayed as a character seeking redemption for past actions, and Natsu could be the catalyst for that change. It's a way to give a new perspective to Zeref's character. Additionally, themes of friendship or unrequited love are also common. The relationship between Natsu and Fem Zeref can be explored in a platonic or romantic way, and often there are misunderstandings and moments of self - discovery related to these feelings.

One possible plot could be that Zeref has a new target in the Naruto universe. Naruto discovers this and decides to confront him. At first, Naruto is outmatched as he doesn't understand Zeref's magic. But then he starts to analyze it during their battles and figures out ways to counter it. Meanwhile, Zeref is intrigued by Naruto's never - say - die attitude and chakra. The plot could also involve other characters from both universes getting involved, either to help or to cause more chaos.

Perhaps the plot could start with Naruto finding out he is Zeref's brother. This revelation could shatter his understanding of his identity. He then embarks on a journey to learn about his past and Zeref's motives. As he delves deeper, he discovers secrets about the two worlds (Naruto's and Fairy Tail's) that are intertwined. He has to deal with the conflict between his loyalty to his new - found family (Zeref) and his own moral compass. Maybe he tries to find a way to save Zeref from his own self - destruction while also protecting the people of both worlds from Zeref's potential threats.

It could be another guild that sees Natsu as a threat. They might find out about Lucy kidnapping Natsu and try to use the situation to their advantage. For example, they could try to steal Natsu's magic or get information out of him while he's in a vulnerable state. Another possible antagonist could be a character who has a grudge against Lucy. They might try to stop her from getting away with the kidnapping or use it as a way to get revenge on her.