Well, obviously Lucy is one of the main characters since it's in the title. She's likely to be the central figure around which the story revolves. There might also be other dragon slayers who could be important characters. They could be friends or rivals to Lucy, and their interactions with her would shape the story.
In some fanfictions, Happy, the flying cat, could also be an important character. He could provide comic relief and also be involved in some of Lucy's adventures as a dragon slayer. For example, he might help her find clues or get out of difficult situations. And then there could be original characters created specifically for the fanfiction. These characters could be other dragon slayers or powerful mages that interact with Lucy in different ways.
One interesting aspect could be how she trains to become a Celestial Dragon Slayer. Maybe she discovers an ancient magic that combines the two, and she has to learn to control the newfound power. This could lead to some great character development as she struggles with the increased power and the responsibility that comes with it.
Perhaps an ancient sorcerer who has the ability to control celestial dragons. He sees Lucy as an obstacle to his domination over the world using the power of these dragons. He would use his vast knowledge of magic and his control over the dragons to try and defeat her.
She could have the ability to breathe celestial - themed 'dragon breath'. For instance, it might be a blast of star - like energy that can pierce through dark magic. Her celestial spirits might also gain new forms or abilities. For example, Aquarius could become a more combat - ready mermaid with dragon - like fins that can slice through water and enemies.
In these fanfictions, a major theme is the combination of different magics. Lucy has her celestial spirit magic and now as a dragon slayer, how these two magics interact and complement each other. Another theme is the search for identity. She is no longer just Lucy the celestial wizard but also a dragon slayer, and she has to figure out what that means for her place in the world and among her friends.
In most 'Lucy the Lightning Dragon Slayer' fanfictions, Lucy herself is front and center. But we also see a lot of the guild master, Makarov. He is often the one guiding Lucy in her journey with her new powers. He gives her advice on how to control it and use it for good. And then there are the other guild members. Happy, for example, might accompany Lucy on some of her adventures and provide some comic relief. The villains in these fanfictions also become important characters as they are the ones that Lucy has to face off against with her lightning - based powers.
One interesting plotline could be Lucy's discovery of her unique powers as a celestial dragon slayer. Maybe she starts off not knowing about this ability and gradually uncovers it through a series of adventures. For example, she might encounter a powerful enemy that only her newfound powers can defeat.
Well, it could start with Lucy being in a situation where she witnesses the destruction caused by a celestial dragon. This event stirs something deep within her, and she decides she wants to be able to protect everyone from such a threat. So, she embarks on a journey to become a celestial dragon slayer. She may travel to different realms or seek out rare magical items that can enhance her abilities. As she progresses, she could form alliances with other powerful mages who share her goal or have knowledge about celestial dragons. And gradually, she builds her skills and reputation as a celestial dragon slayer.
It could be another powerful celestial dragon who opposes Lucy's ideas or presence.
Sure. One popular 'Lucy is a celestial dragon slayer' fanfiction is 'Lucy's Ascent'. It shows Lucy's journey as she discovers her unique slayer abilities and battles powerful foes. Another great one is 'Celestial Dragon Slayer Lucy' which focuses on her training and the relationships she forms along the way.