There could also be a plotline where they both discover a new magic together. While exploring this new magic, they have to train closely and that physical and mental closeness could spark a romantic relationship. Maybe it's a long - lost ice - and - celestial - combined magic that only they can master, and as they figure it out, their relationship evolves.
In some fanfictions, Lucy and Gray could leave Fairy Tail due to a prophecy. They believe that their presence in the guild will bring danger to their friends. So, they leave secretly. On their journey, they discover secrets about their own powers and pasts that they never knew before. They also encounter old enemies who are now after them for leaving Fairy Tail as it disrupts the balance of power that was maintained in the guild's territory.
Often, there could be a plotline where Gray is forced into a situation that makes it look like he's cheating. Say, an enemy of Fairy Tail frames him by creating false scenarios. Or it could be a situation where Gray is trying to protect Lucy from a greater danger by getting closer to someone else, but Lucy doesn't understand his intentions at first. There are also plotlines where Gray's past comes back to haunt him and his interactions with an old acquaintance seem like cheating to Lucy.
Another common plot is Gray getting jealous when Lucy is getting too much attention from other guys in the guild. This jealousy leads to some really interesting interactions between them, like Gray trying to show off in front of Lucy in a really cute and clumsy way.
There are also storylines that focus on their friendship growth. Maybe they start off not getting along well because of their different personalities. Gray is more stoic and Lucy is more outgoing. But then through various adventures together, they come to understand and respect each other, and this forms a deep bond of friendship that is central to the fanfiction.
A lot of fanfictions focus on the idea of Natsu and Lucy being forced to work together in a tournament. They have to overcome their differences and use their combined skills to win. This often leads to a better understanding of each other. There are also plotlines where Lucy discovers a new and powerful form of her celestial magic and Natsu helps her master it. Sometimes, a prophecy about their combined destiny is revealed, which sets them on a journey to fulfill it.
One interesting plotline could be a magic - based adventure where Erza and Lucy team up against a powerful dark mage. They might use their unique magical abilities in tandem, like Erza's requip magic and Lucy's celestial spirit magic to overcome challenges. For example, they could be on a quest to retrieve a powerful magical artifact that has been stolen by the dark mage. Along the way, they strengthen their friendship and learn new magical techniques from each other.
A good one often has well - developed characters. It should stay true to the personalities of Lucy and Gray from the original 'Fairy Tail' series. Their relationship should be built up gradually, with believable interactions and chemistry.
One popular theme could be friendship. In Fairy Tail, friendship is a strong element, and in Lucy - centered fanfictions, it might show how her friendships, especially with characters like Natsu, develop in new and interesting ways. For example, they could go on a different kind of adventure together that wasn't in the original series.
Well, a common theme is the power of their combined magic. In fanfiction, writers might imagine new spells or abilities that come out when Gray's ice - make magic and Lucy's celestial spirit magic work together. It can be really exciting to see how they use their unique powers in unison. And of course, there are the lovey - dovey themes. Such as how Gray might be protective of Lucy in dangerous situations, which is a sign of his growing love for her. And Lucy might be the one to break through Gray's cold exterior with her warm and kind nature.
One popular scenario could be during a dangerous mission. Maybe they're trapped in a magical cave, thinking they might not make it out alive. In that moment of high emotion and closeness, they share a kiss. It's a way to express their unspoken feelings for each other that have been building up throughout their adventures together.