Yang might also be a good friend. Yang is strong and protective. She could see Kirby as someone in need of protection at first, but then grow to respect his abilities. They could bond over their love of a good fight and Yang could teach Kirby some combat moves that work well in Remnant.
Pyrrha could be a friend to Kirby. She is very skilled and has a noble personality. She could help Kirby learn about the concept of auras and semblances in Remnant. And Kirby, with his unique abilities, could offer Pyrrha a different perspective on combat and power.
Ruby could be a great friend for Kirby. They both have a sort of innocence about them. Ruby's love for adventure and her kind heart would make her open to befriending Kirby. They could go on adventures together and Ruby could help Kirby understand the world of Remnant.
A cool plot might involve a dark force that is affecting both the RWBY world and Kirby's world. This force is causing strange things to happen, like Grimm starting to appear in Dream Land and some of Kirby's enemies showing up in Remnant. Ruby, Weiss, Blake, and Yang meet Kirby, and they initially don't understand him but soon realize his power. They work together to find the source of this dark force. Kirby uses his inhale ability to help them gather information by sucking up some of the smaller Grimm and enemies to learn more about what's going on.
One common theme is the contrast between the two universes. RWBY is a darker, more complex world with themes of war, discrimination, and personal growth. Kirby's world is much more light - hearted and simple. So, when combined, it often leads to themes of how different personalities and powers interact. For example, Kirby's innocent nature might contrast with the more battle - hardened RWBY characters.
Well, in such a fanfiction, game Kirby could introduce anime Kirby to the more traditional power - ups from the games. Meanwhile, anime Kirby could show game Kirby some of the unique storylines and character interactions that are common in the anime. Maybe they would have a friendly competition to see who can inhale and defeat enemies faster. It would be a really interesting crossover with a lot of potential for fun and adventure.
One popular Kirby and RWBY fanfiction could be those that involve Kirby characters in the RWBY universe, like Kirby joining Team RWBY on their adventures. Maybe he uses his unique abilities to help them fight Grimm. Another type might be where RWBY characters are transported to the Kirby world and have to adapt to its strange and colorful environment.
Kirby and Yang could also make an interesting pairing. Yang is strong and brash, while Kirby is small but mighty. Their personalities contrast but could also complement each other well. Yang could provide the brute force while Kirby could use his unique powers to support her in battles, like when she's facing a particularly tough Grimm.
Blake and Kirby would also be a great combination. Blake has a mysterious side to her, with her Faunus heritage and her past. Kirby's innocent and curious nature could make Blake open up more. And Kirby might be intrigued by Blake's ability to use her shadow and her skills as a Huntress. Their relationship could develop in ways that explore both their characters' depths in the RWBY x Kirby fanfiction world.
Definitely Naruto. Naruto would be curious about Kirby's abilities and would probably want to be friends right away. They could have some fun training sessions together, with Kirby showing off his inhaling skills and Naruto his new Rasengan variations. Also, Sakura might interact with Kirby. She could be initially a bit skeptical but would come around when she sees how Kirby can be helpful in medical situations by using his powers to quickly gather medicinal herbs or supplies.
In such fanfiction, Kirby is often depicted as his cute, round self, but with a more tender side when it comes to his feelings for Jigglypuff. He might use his unique abilities to protect or impress Jigglypuff.
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.
One idea could be Kirby arriving in Remnant and being mistaken for a new type of Grimm at first. Then, as the characters get to know Kirby, they realize his unique abilities can be a great asset in battles against Salem's forces.