I think Natsu and Ruby would be an interesting pairing. Natsu is impulsive and powerful with his fire magic, while Ruby is young and enthusiastic with her scythe skills. They could bond over their love for adventure and their desire to protect their friends. They might also learn new ways to fight from each other, like Natsu learning about Ruby's speed and Ruby learning about Natsu's raw power.
I think Natsu and Ruby would be an interesting pairing. Natsu is all about brute force and his love for fighting, and Ruby has her own determination and speed. They could learn from each other's combat styles. Ruby could show Natsu how to be more strategic with his attacks, while Natsu could teach Ruby how to be more fearless in the face of danger.
Gray and Weiss could also make a great pair. Gray with his ice - make magic and Weiss with her ice - based semblance could have some really cool interactions. They could compare and contrast their ice powers, and perhaps even combine them in some creative ways during battles. Plus, their personalities are quite different which would lead to some interesting character development moments.
Lucy and Albedo could also make for an interesting pair. Lucy is a strong - willed mage with her own set of celestial keys, while Albedo is extremely loyal to Ainz. Their interactions could explore themes of loyalty and friendship, as Lucy tries to understand Albedo's devotion to Ainz while also showing her own loyalty to her Fairy Tail friends.
Lucy and Eevee could be an interesting pair. Lucy is kind - hearted and Eevee is a very adaptable and cute Pokemon. Lucy could use her celestial keys to help Eevee evolve into different forms depending on the situation they are in. For example, if they need to cross a large body of water, she could help Eevee evolve into Vaporeon.
Natsu and Ziva would make an interesting pairing. Natsu's hot - headedness and powerful fire magic could contrast well with Ziva's cool and efficient combat skills. They could learn from each other in terms of fighting styles and also develop a friendship based on mutual respect.
Fred and Erza would make an interesting pairing. Fred is used to being the leader in solving mysteries, and Erza is a strong and fearless leader in Fairy Tail. They could combine their leadership skills to lead the group in solving a complex mystery or fighting a powerful enemy.
Robin and Mirajane would be a great match. Robin is calm, intelligent, and has her unique devil fruit powers. Mirajane is kind - hearted but also has her powerful Satan Soul forms. They could bond over their love for their friends and families, and Robin could learn more about magic from Mirajane while Mirajane could be fascinated by Robin's knowledge of the world's history.
Yugi and Natsu would be an interesting pairing. Yugi is calm and strategic, while Natsu is impulsive and powerful. They could balance each other out. Yugi could use his intelligence to plan their adventures, while Natsu could use his fire - based magic to fight off enemies. Another interesting pair could be Erza and Kaiba. Erza is a strong and disciplined warrior, and Kaiba is a proud and powerful Duelist. They could have some epic battles of wills and skills.
Spiderman and Erza would make for a strong pairing. Erza is a very powerful and disciplined mage. Spiderman could be in awe of her combat skills and leadership. They could fight side - side against powerful enemies, with Spiderman using his webs and agility and Erza with her various armors and weapons.
Definitely Naruto and Natsu. They are both the main protagonists in their respective series and have a lot of energy and a strong sense of justice. Their interactions would be really fun to read, like when they compete to see who can defeat the most enemies or who has the stronger fire - related power.