If Lucy never joined Fairy Tail, the friendships and relationships among the characters would form in a very different way. Also, many of the story arcs might not unfold as they do in the original plot.
Natsu would probably be very confused and sad at first. He's used to having Lucy around, and her sudden departure would leave a big hole in his daily adventures. He might try to convince her to come back immediately.
Well, if we consider Lucy as a Dragon Slayer in fanfiction, her magic could be really different from the traditional ones. Maybe she'd have a connection to a celestial dragon, which would be so cool. It would combine her existing celestial spirit magic with the new dragon slayer powers. She could use the stars as a source of power, similar to how other dragon slayers use elements, and it would be a fresh take on her character.
You can try searching on fanfiction websites like Archive of Our Own or FanFiction.net. Just type in 'Lucy Frosch Fairy Tail' in their search bars, and you might find relevant fanfictions.
One great nonhuman Lucy fanfiction could be where she's a celestial spirit herself. In this type of story, Lucy might have a deeper connection with the celestial world. She could understand the spirits in a more profound way and have unique powers that normal humans in Fairy Tail don't possess. This would lead to interesting adventures and interactions with other guild members who are initially surprised by her new form.
There's a fanfic titled 'Married Life in Magnolia' which focuses on their day - to - day married life. It includes Natsu being his usual goofy self and Lucy trying to keep him in line while they both deal with the challenges of being a married couple in the Fairy Tail guild.
One possible fanfiction could be that Lucy is invited to a grand ball in the magical world. As she enters the ballroom, a mysterious melody starts playing. Lucy, being the confident and graceful character she is, starts to dance. Her celestial spirits watch in awe as she twirls around, her dress flowing with each movement. It could be a dance that not only showcases her beauty but also her connection to the magic within her, as she uses a bit of her magic to create a sparkling effect around her while she dances.
Another fanfic could focus on Lucy's relationship with Erza. Maybe they team up for a tournament within the Fairy Tail guild. Along the way, they face tough opponents and have to rely on each other's strengths. Lucy's strategic thinking combined with Erza's powerful combat skills would make for an exciting story.
In some fanfictions, Lucy might be portrayed as a friend to Frosch. She could be someone who looks out for the little Exceed, given her kind - hearted nature in the Fairy Tail series.