Growth could also be a theme. Nashi would be growing up, learning about her powers (if she has any), and about the world around her. Natsu and Lucy would also be growing as parents, learning how to take care of a child, make decisions for the family, and balance their previous lives with their new roles as parents.
In the 'natsu and lucy baby nashi fanfiction', we can expect a lot of heartwarming scenes. Natsu and Lucy would surely have to adjust their lives. Nashi might inherit some of their powers or traits. There could be a story arc about Nashi growing up and wanting to follow in her parents' footsteps. The fanfiction might also show how their friends in the story react to the new addition to the family, and how they all contribute to Nashi's upbringing.
One possible theme could be about facing unexpected challenges. Natsu and Lucy would have to deal with the reactions of their friends, family, and schoolmates. Another theme might be growth and maturity as they are forced to grow up quickly due to the pregnancy.
Well, there are several potential plots for this kind of fanfiction. Maybe Natsu is in an environment where he is constantly bullied and abused, like in a guild where some members are jealous of his power. Lucy, who has a kind heart, decides to take him under her wing. She might teach him self - defense or help him build his self - esteem. Another plot could involve Natsu being abused due to a family secret or a prophecy that makes others target him. Lucy, with her intelligence and courage, tries to rewrite the fate that seems to doom Natsu to abuse. This could involve going on quests to find artifacts or information that can change the situation.
Well, perhaps in this fanfiction, Natsu calling Lucy 'baby' is a sign of a new level of closeness in their relationship. It could start with Natsu protecting Lucy in a dangerous situation and instinctively calling her 'baby' as he holds her close. This then leads to Lucy being a bit flustered at first but gradually getting used to it and even liking it, and it becomes a special part of their bond.
One possible plot could be that Natsu and Lucy accidentally end up taking care of a baby dragon. They struggle at first with things like feeding it and getting it to sleep. But as time goes on, they grow attached and learn a lot about themselves and their relationship in the process.
Well, perhaps the story could start with Lucy finding out she's pregnant. Natsu is initially shocked but then becomes super excited. The pregnancy is filled with little adventures, like Natsu trying to build a perfect nursery using his magic in a rather clumsy way. And when the baby is born, it brings a new sense of hope and family to the whole guild. Everyone pitches in to take care of the baby, and it grows up surrounded by love and magic.
Well, it could be about Nashi going on an adventure with Natsu. Maybe they discover a new magic together and have to fight some bad guys to protect their world.
One possible plotline is that Natsu starts writing in the diary about his confusion regarding his feelings for Lucy. He might write about how he gets jealous when other guys show interest in her. Another plot could be that Lucy accidentally discovers the diary and confronts Natsu about it, which then leads to them finally admitting their feelings for each other.
Well, it could be that Lucy has a misunderstanding. Maybe she overhears something that makes her think Natsu is planning to leave the guild without saying goodbye. So, in a fit of panic and anger, she kidnaps him to get an explanation. Then, as the story progresses, they have a heart - to - heart conversation where the misunderstanding is cleared up. It could also be a situation where Lucy is competing with someone else for Natsu's attention, and she thinks that by kidnapping him, she can have him all to herself for a while and figure out how to make him like her more.
One common theme is adventure. Since they are from the Fairy Tail guild which is all about going on quests, many fanfictions continue this trend. They go on new adventures together, facing powerful enemies and discovering new magic.