I think Ruby and Nagisa would be a great pairing. Ruby is all about being a hero and has her own sense of justice, while Nagisa has been trained to be an assassin but also has a good heart. Their different outlooks could lead to some really interesting conversations and adventures.
One of the most interesting pairings would be Weiss and Kayano. Weiss is from a high - class family and has a very formal way of doing things, while Kayano is more free - spirited. Their clashing personalities could lead to some comical moments at first. But as they get to know each other, they could learn a lot from one another. Also, Pyrrha and Sugaya could be an interesting pair. Pyrrha is a famous and skilled fighter, and Sugaya is good at art and has his own unique combat style. They could exchange knowledge about combat and different forms of self - expression.
Midoriya and Nagisa would be an interesting pairing. Midoriya is all about becoming a great hero and has a powerful Quirk that he's constantly learning to control. Nagisa, on the other hand, is a skilled assassin - in - training with great stealth. They could learn a lot from each other. Midoriya could teach Nagisa about the importance of having a big dream and standing up for what's right in a more heroic sense, while Nagisa could show Midoriya how to be more stealthy and observant.
Definitely Nagisa. In the crossover, he could be the one who has the hardest time adapting to the new world of KHR. His assassin skills would be put to the test in a different way compared to Assassination Classroom. He might form an interesting friendship with Tsuna, as both are somewhat timid at first but have great potential within them.
Ruby and Cayde - 6 would be an interesting pairing. Ruby is young and full of energy, always eager to learn and fight. Cayde - 6 is a witty and experienced Guardian. Their interactions could be really fun, with Cayde - 6 teaching Ruby some of his trick - shooting skills and Ruby showing Cayde - 6 the beauty of her Crescent Rose. Another great pairing would be Weiss and Ikora Rey. Weiss is a highly - trained fighter with a strong sense of discipline, and Ikora Rey is a powerful Warlock with great knowledge. They could share their knowledge of magic - like abilities, Weiss with her Glyphs and Ikora with her Light - based spells. Yang and Zavala could also be an interesting pair. Yang is all about brute strength and a go - getter attitude, while Zavala is a respected leader. Yang could learn about leadership from Zavala while Zavala could admire Yang's tenacity.
Ruby and a Skaven Assassin could be an interesting pairing. Ruby with her speed and scythe skills would be pitted against the sneaky and devious Skaven. It would be a battle of wits and speed. Another great pairing could be Weiss and a High Elf Mage. Weiss's elegance and ice powers could contrast and interact with the Elf's magic. And Yang and a Chaos Space Marine. Yang's brute strength and brawler style against the super - powered and corrupted Chaos Space Marine would make for an intense fight.
The Doom Slayer and Ruby would be an interesting pairing. Ruby is young and full of energy and hope, while the Doom Slayer is a silent, stoic force of destruction against evil. Their interactions could be really cool, like Ruby trying to understand the Doom Slayer's lack of words but seeing his determination and being inspired by it. And the Doom Slayer might see Ruby's potential and unwavering spirit in the face of danger as something similar to his own.
Ben and Ruby would be an interesting pairing. Ruby is young and full of energy, always eager to learn and improve. Ben, with his experience using the Omnitrix, could teach her a lot about adapting to different situations. And Ruby could show Ben the importance of teamwork in her own unique way.
Yang and Kenpachi would be a wild and exciting pairing. Yang is all about brute strength and has a bit of a hot - headed nature. Kenpachi is the same, always looking for a good fight. They could have some epic battles together, or team up and be an unstoppable force. Also, Blake and Urahara could be an interesting pair. Blake is stealthy and intelligent, and Urahara is a mastermind with all kinds of tricks up his sleeve. They could scheme together to solve the problems that come up in the crossover world.
Naruto and Ruby would be an interesting pairing. Naruto's energetic and positive nature would contrast and complement Ruby's own enthusiasm and leadership. They could bond over their shared goal of protecting their respective worlds and learn from each other's combat styles. Ruby could learn about Naruto's Rasengan while Naruto could be intrigued by Crescent Rose.
Ruby and Yu Narukami. Ruby is young and full of energy, always eager to fight for what's right. Yu is a calm and collected leader. Their different personalities would make for an interesting dynamic. Ruby could learn from Yu's more methodical approach to problem - solving, while Yu could be inspired by Ruby's unwavering determination.
Ruby and Kirby would be an interesting pairing. Ruby is fast and has her scythe skills, while Kirby has his unique powers. They could both be the impulsive and eager ones in the group, always ready to jump into action. Ruby could be amazed by Kirby's ability to copy powers, and Kirby could be intrigued by Ruby's Crescent Rose.