Obviously, Laxus is the central character. He is a powerful mage in the Fairy Tail guild. His character is often explored in terms of his growth, his relationships with other guild members like Natsu and Erza.
One great Lucy x Laxus fanfiction is 'A New Bond'. It focuses on how they start to rely on each other during a difficult mission. Their interactions are really well - written, with Lucy's kind heart slowly melting Laxus's tough exterior.
One great Fairy Tail Laxus fanfiction is 'Laxus' Redemption'. It delves into his journey of making up for his past mistakes and growing as a character. The story beautifully portrays his relationships within the guild.
A strong plot is also essential. It could be a story about them going on an adventure together, or dealing with a threat to the guild that brings them closer. The plot should not feel forced, but rather flow naturally as their relationship evolves. For instance, a plot where they have to team up to defeat a powerful enemy can create great opportunities for their relationship to grow.
Perhaps she decides to go on a solo adventure to find out more about her family's past. This journey takes her to far - off lands where she meets different characters and has to overcome various challenges. When she returns to Fairy Tail, she has new knowledge and experiences that change the way she interacts with the guild and especially with Laxus.
Her character could be developed by showing her struggle with living in Laxus' shadow. She might start off as a bit timid but gradually become more confident as she finds her own place in the guild. For example, she could take on small tasks around the guild and prove her worth.
A really interesting plot would be if there was a prophecy about Freed and Laxus having to team up to save the Fairy Tail guild from an internal threat. They would have to face their own insecurities and past mistakes while trying to figure out who the traitor in the guild is. Along the way, they would strengthen their bond and prove their loyalty to Fairy Tail.
A plot could involve Fem Natsu accidentally using her magic in a way that affects Laxus in an unexpected manner. For example, her fire magic could trigger some latent power in Laxus, and as they figure out what's going on, they become closer. This could also lead to some interesting training sessions between them as they try to control this newfound power connection.
Their relationship could develop realistically through shared experiences. For instance, if they both have to protect a young mage from a common enemy. This shared responsibility would force them to communicate more, understand each other's strengths and weaknesses, and gradually form a bond.
In a crossover with 'One Piece', they could be paired with Luffy. Luffy's carefree and determined nature would contrast well with Freed and Laxus. They could all be on a quest to find a magical treasure that has power over both their worlds. Luffy's Gum - Gum powers would be interesting to see alongside Freed's rune magic and Laxus' lightning.