How would the characters in Fairy Tail react to Sting and Rogue joining in a fanfiction?

One idea could be that Sting and Rogue initially come to Fairy Tail as spies for Sabertooth, but as they interact with the Fairy Tail members, they start to question their loyalty to their old guild. They could be paired up with different Fairy Tail mages on missions. For example, Sting with Natsu and Rogue with Gray. Through these experiences, they see the true meaning of friendship in Fairy Tail which is different from the competitive environment in Sabertooth.

For Lucy, you could develop her character by showing her growing more confident in her magic. Maybe she starts to experiment with new ways to summon her Celestial Spirits or combines their powers in unique ways. With Sting, you can explore his past more deeply. Show how his experiences as a Dragon Slayer have shaped his personality, and have him face some internal conflicts related to his power and identity. As for Rogue, you could develop his relationship with his shadow. Maybe he discovers new abilities within his shadow magic. Also, in the fanfiction, put them all in situations that force them to interact and grow together. For example, a mission where they have to protect a village from a powerful dark mage.

Natsu would probably be really excited at first. He loves dragons and having a dragon king around would be like a dream come true for him. He'd probably want to immediately challenge Tiamat to a fight to test his strength. Erza, on the other hand, would be more cautious. She'd be on guard, making sure that Tiamat doesn't pose a threat to the guild. Gray might be a bit indifferent at first, but as he sees how Tiamat could be useful in battles, he'd start to warm up to the idea.

Another common theme is power and growth. Writers often show how Rogue and Sting become stronger over time. For example, they might face a powerful enemy and through that experience, they learn new magic or improve their existing skills. It's about their journey to become more powerful dragonslayers.

For Lucy, you could explore her celestial spirit powers more deeply. Maybe she discovers a new and rare spirit that has a special connection to Rogue or Sting's magic. For Rogue, his relationship with his shadow could be further developed. He might learn to use his shadow in new ways, and Lucy and Sting could play a role in that discovery. For Sting, his leadership skills could be tested and improved. They could be put in a situation where Sting has to lead a group that includes Lucy and Rogue, and he has to make tough decisions.

Natsu could be a great character to pair them with. Since he's also a dragon slayer, there could be some interesting interactions and competitions among them. They could learn from each other's dragon slayer techniques.

Friendship is a very common theme. Sting and Rogue are often depicted as having a deep and unbreakable friendship. Another theme is adventure. They go on various adventures together in many fanfictions. And of course, the theme of magic is always there as they are part of the Fairy Tail world which is full of magic.

The members of Fairy Tail would likely be shocked and angry. They would feel betrayed because Naruto had probably become a part of their family. Natsu, for instance, would be enraged and might immediately challenge Naruto to a fight. He's hot - tempered and wouldn't take kindly to someone he considered a friend turning against the guild.

The characters in Fairy Tail would have a wide range of reactions. Makarov, as the guild master, would be very cautious. He would need to ensure that Acnologia's presence doesn't put the guild in more danger. Happy would be constantly on guard around Acnologia, ready to fly away at the first sign of trouble. The Thunder Legion would likely be in a state of high alert. However, some of the more adventurous members like Cana might see it as an opportunity for great adventures and powerful new magic. It would be a complex situation with different characters having different stances based on their personalities and past experiences.

A possible plot could involve a dark magic that starts affecting Fiore. Lucy discovers some ancient texts about it, and she realizes she needs the help of Sting and Rogue. They go on a journey to find the source of this dark magic. Along the way, they encounter many enemies. Sting and Rogue use their Dragon Slayer magic to fight, while Lucy summons her Celestial Spirits. As they get closer to the source, they find out that one of their old enemies has returned and is using this dark magic to seek revenge. Together, they combine their powers to defeat the enemy and save Fiore.