A more complex plot could involve Red Velvet members having semblances (like in RWBY) and they team up with the RWBY girls to fight a new, powerful enemy that threatens both their worlds. This would allow for a lot of character development and cool fight scenes.
One plot idea could be a crossover where the characters from RWBY and Red Velvet are in a singing competition in a magical world. It combines the combat elements of RWBY with the music and charm of Red Velvet.
One idea could be a story where Fox and Velvet go on a mission together outside of Beacon. They encounter a new type of Grimm that they have to figure out how to defeat. Along the way, they learn more about each other's fighting styles and personalities.
One idea could be a story where the Red Queen character has to team up with the RWBY team to fight a new, powerful Grimm that is immune to normal attacks. This would force them to combine their unique abilities in unexpected ways.
One plot idea could be Velvet getting involved in a mysterious adventure where she discovers a hidden power within herself. Maybe she teams up with some unlikely allies and they have to face a powerful enemy. Another idea is a story centered around Velvet's relationships, like a budding romance with a character from her world, and how she navigates the challenges that come with it.
One idea could be that the Reds and Blues get transported to the RWBY world and have to learn how to use Dust to fight. They could team up with Team RWBY and face off against a new enemy that is a threat to both their universes. Maybe they introduce their unique sense of humor and combat styles to the RWBY characters.
One plot idea could be that Ruby's red eyes start to have a strange glow that gives her the ability to see into the future, but only in brief glimpses. She has to learn to use this new power to stop a new threat that no one else can detect yet.
Maybe a story where the Reds and Blues are transported to the RWBY world. They have to learn about Grimm and Huntsmen while trying to find a way back home. Along the way, they could team up with RWBY characters like Yang, who could teach them some hand - to - hand combat skills, which are different from their usual long - range tactics.
One plot idea could be the characters from Red vs Blue and RWBY teaming up to fight a common enemy. For example, a powerful Grimm that has somehow entered the Red vs Blue universe. Another could be the Reds and Blues getting involved in the Beacon Academy's classes and causing chaos with their unique combat styles. Maybe they could introduce their own brand of humor to the more serious RWBY world.
There might be a fanfiction where Velvet teams up with some European - based Huntsmen or Huntresses. They could face unique Grimm threats that are specific to the European - like regions in the RWBY world. For example, Grimm that are based on European folklore monsters.
One interesting Velvet RWBY fanfiction could be 'Velvet's Adventure'. In this story, Velvet might go on a solo mission where she discovers new abilities. Another could be 'Velvet and the Lost Relic', where she teams up with other characters to find a powerful relic. There are also fanfictions that focus on Velvet's relationships, like 'Velvet's Friendship Bonds' which explores her friendships in a more in - depth way.
One idea could be a team - up between Ruby from RWBY and the Red team from Red vs Blue. They could face a common enemy that requires both their unique skills. For example, a new type of Grimm that has advanced technology, and the Reds' combat knowledge combined with Ruby's speed and scythe - wielding abilities would be needed to defeat it.