Another character that could be affected is Makarov. As the guild master, he would have to deal with Lucy joining at an earlier time. He might have to allocate different tasks or missions for her, based on her level of experience at that point. Also, characters like Mirajane might have different conversations with Lucy earlier on. For instance, Mirajane could be the one to give Lucy a tour of the guild right when she joins, instead of later in the original timeline.
Erza would be one of the main characters affected. In the original story, when Lucy joins, Erza has a certain perception of her. But if Lucy joins earlier, Erza might see her as a more inexperienced mage and take her under her wing even more. Gray might also have different interactions with Lucy. He could be more of a mentor figure to her in the beginning, teaching her about controlling her magic in cold environments, which is something he's good at.
In this fanfiction, perhaps Lucy joins Fairy Tail right after she discovers her magic abilities. This would change a lot of the initial interactions. She could be more naive and inexperienced when joining, which would lead to different dynamics within the guild. Like, she might be more reliant on the others for guidance in using her magic, rather than having some basic skills already when she actually joins in the original story.
Lucy and Natsu are the central figures. Their relationship is at the core of this fanfiction. Lucy uses her wits and charm to tease Natsu, and Natsu responds with his typical fiery and passionate reactions. Their interactions are what drive the story forward, and any other characters that appear are there to either enhance or complicate their relationship dynamic.
The main characters are clearly Lucy and Natsu. Lucy is a celestial wizard in the Fairy Tail guild, known for her kind heart and determination. Natsu is a dragon slayer, hot - headed and powerful. In this fanfiction, their relationship is the focus, with Lucy taking the initiative to get closer to Natsu in a seductive way.
Maybe they leave because they want to search for answers about their pasts. Happy might want to know more about his origins, and Lucy could be seeking something related to her family's history.
Natsu would be a likely character to comfort Lucy. He's her close friend and often there for her. His warm and energetic nature could cheer her up. Another one could be Erza. Erza is strong and reliable, and she has a soft spot for her guildmates. She would probably offer Lucy some wise words and a shoulder to cry on. Happy, the little blue exceed, might also be there. His cute antics and friendly presence could make Lucy feel better.
Natsu would be a very likely character. Since he and Lucy are close friends in the original story, if Lucy travels back in time, Natsu might be one of the first people she seeks out. They could have adventures together in the past, with Natsu being his usual impulsive self and Lucy having to keep him in check with her knowledge of the future.
Gray could be another great pairing. The contrast between his cool - headedness and Lucy's more emotional nature could create interesting storylines. For instance, they might be forced to work together on a mission where their differences initially cause problems but later lead to a stronger bond.
There could be a wandering mage at her home. This mage might be on the run from some powerful enemy and has sought refuge at Lucy's place. Lucy then has to decide whether to help the mage or turn them in, all while dealing with the potential danger this might bring to her and her family.
A group of rogue mages who oppose the idea of Yukino joining Fairy Tail. They might view Fairy Tail as a threat to their own plans in the magical world. They target Yukino as the 'newcomer' in the guild, thinking that if they can get rid of her, they can weaken Fairy Tail. They use various underhanded tactics like spreading false rumors about Yukino within the guild and attacking her when she is on solo missions.
Perhaps an old enemy of Fairy Tail who sees Natsu as a new threat. They might target Natsu specifically to prevent him from strengthening the guild. This antagonist could have a long - standing grudge against Fairy Tail and see Natsu as the new hope for the guild, so they try to eliminate him before he can fully join.