Gray could also be a possibility. He and Lucy have a friendly rivalry and there are moments where their relationship could be interpreted as having deeper feelings. It would be an interesting twist if Gray was the father, as it would change the dynamics between him, Natsu, and Lucy in the fanfic.
Well, if we're following the common ships in the Fairy Tail fandom, Natsu could be a likely candidate. Their relationship is very close and there are many hints of a deeper connection between them in the original series. It would make for an interesting story as Natsu would have to grow up a bit to take on the role of a father.
Well, one possibility could be that the story focuses on how Lucy adjusts to her new state. Maybe she has to cut back on her guild missions at first. She might worry about how Natsu and the others will react. It could also involve her having strange pregnancy cravings that lead to some comical moments in the guild. And as her pregnancy progresses, she could start preparing a nursery in her home, all while still being part of the Fairy Tail family.
It could be a heroic character she meets during her quest. Maybe a powerful wizard or a brave knight who has a brief but intense encounter with Lucy, leading to her pregnancy.
One idea could be exploring how the other members of Fairy Tail support Lucy during her pregnancy. For example, Natsu might be overprotective, always making sure she's safe on missions or just in general. Another could be Lucy writing in her diary about her hopes and fears for the future as a mother, while also reflecting on her adventures in Fairy Tail.
It could be that there are some internal issues within Fairy Tail that make her leave while being pregnant. For example, there might be a prophecy or a curse that she believes could harm her baby if she stays. So, in order to break free from that potential threat, she decides to leave. Also, she may be facing some personal conflicts with other members of Fairy Tail regarding her pregnancy, like some not being supportive or having different views on how she should handle it, which ultimately drives her to leave.
It could be a rogue Dragon Slayer who is jealous of Lucy's new - found powers. This character might have been exiled from their own guild for misusing their powers and now sees Lucy as an easy target to prove their superiority.
The father of the baby could be a major character. He could be a loving partner, or there could be some drama if he's not as committed as Lucy. Her best friend could also be in it. The best friend might be the one she confides in about all her pregnancy fears and joys.
One possibility is that it's a fanfic set in an alternate universe where Sting has a special connection with Lucy. They might discover a new form of magic together. For example, Sting's white dragon slayer magic could combine with Lucy's celestial spirit magic in an unexpected way, leading to a whole new set of adventures.
One possibility is that it focuses on a love story between Lucy and Rufus. They start off as rivals, perhaps competing in a magic competition. But as they get to know each other better, they realize they have more in common than they thought and fall in love. This could involve them sharing their dreams and fears, and overcoming obstacles together to be with each other.
One possible plot could be that Rogue somehow gets transported to Lucy's world and they have to figure out how to get him back. During this time, they start to understand each other better. Lucy might learn about Rogue's past and his struggles, and Rogue could see the kindness and strength in Lucy. They could develop a friendship or something more as they face various challenges in the Fairy Tail world.