Blake and Joey could be paired up. Blake's mysterious and independent nature would contrast well with Joey's more hot - headed and passionate personality. They could support each other in different ways, like Blake using her stealth to help Joey in a tough situation, and Joey's loyalty inspiring Blake.
Master Chief and Ruby could be an interesting pairing. Master Chief's stoic and experienced nature could contrast with Ruby's more youthful and enthusiastic personality. They could learn a lot from each other in combat situations.
One idea could be a crossover tournament where RWBY characters and Yugioh duelists compete. For example, Ruby could use her speed to quickly draw cards. Another could be a story where the Grimm from RWBY are somehow affected by the magic in Yugioh cards. Maybe they become more powerful or get some new abilities.
Ruby and Sans are quite popular. Ruby's energetic and positive personality contrasts well with Sans' lazy - yet - deep - thinking nature. Their interactions can be really interesting as they come from such different worlds but share a certain sense of humor. Another popular pairing is Weiss and Papyrus. Weiss' elegance and determination can play off Papyrus' over - the - top confidence and his own sense of honor in a really engaging way.
Chazz and Bakugo from My Hero Academia. Chazz's prideful and often - prickly personality would clash and also complement Bakugo's explosive and over - confident nature. They could start off as rivals in a new crossover world, constantly trying to outdo each other in various challenges, whether it's dueling or using their quirks.
Yugi and Ash could be an interesting pairing. Yugi's strategic mind from Yu - Gi - Oh duels could help Ash in his Pokemon battles. And Ash could introduce Yugi to the world of Pokemon training. Another pairing could be Kaiba and Gary. They both have that competitive streak. Kaiba might be intrigued by Gary's skills as a Pokemon trainer and Gary could be interested in Kaiba's high - tech Duel Disk.
Ruby could interact with the main characters from Red vs. Blue. Maybe she tries to teach them some of her scythe - fighting techniques, and in return, they show her some of their military - style combat strategies. It would be an interesting exchange of skills.
Ruby and Church could be an interesting pairing. Ruby is young and idealistic, while Church is often sarcastic and has a more jaded view. Their interactions could be really fun to read. Another would be Weiss and Tucker. Weiss is from a high - society background and Tucker is, well, Tucker. The contrast in their personalities and upbringing would make for an engaging story.
Reinhardt and Yang would be quite a pair. Reinhardt is the fearless crusader with his rocket - powered hammer and shield, while Yang is a brawler with her gauntlets. They could have some epic battles side by side, and Yang could learn about honor and chivalry from Reinhardt, while Reinhardt could be impressed by Yang's tenacity and determination in the face of danger.
One of the most interesting pairings would be Reinhardt and Pyrrha. Reinhardt is a knight - like character in Overwatch, and Pyrrha was a very skilled fighter in RWBY. They both have a strong sense of honor. Reinhardt could teach Pyrrha some of his combat techniques from the Overwatch world, and Pyrrha could show Reinhardt some of the unique fighting styles in RWBY. Also, Widowmaker and Weiss could be an unexpected but fascinating pairing. Widowmaker's cold - blooded assassin nature could contrast with Weiss' more noble upbringing, and they could learn from each other in terms of combat and strategy.
Naruto and Ruby would be an interesting pairing. Naruto's positive attitude and never - give - up spirit could mesh well with Ruby's determination. They could both inspire each other in combat and in their personal growth. Another good pairing could be Sasuke and Blake. Sasuke's brooding nature and his search for power could be contrasted with Blake's own past and her fight for equality. They could have some deep conversations about their motives and past traumas.