Maybe there's a competition in the RWBY world similar to a rock concert battle. Different teams, including our main RWBY characters, compete by performing music - inspired by 'We will rock you'. And the winner gets some kind of special reward or power - up.
A possible plot could be that Iron Man's technology somehow gets transported to the RWBY universe. RWBY characters find it and try to figure out how to use it against the Grimm. Iron Man then arrives in this universe to retrieve his tech and ends up teaming up with the RWBY gang.
One possible plot twist could be that RWBY initially believes Salem's motives are good. Since she raised them, they might be blind to her true evil nature at first. For example, Salem could have presented herself as a protector against some other greater threat, making RWBY question their newfound allies when they start to oppose Salem.
Maybe Reese is a new student at Beacon Academy, and Ruby is assigned to be her guide. Ruby shows Reese around the school, introduces her to their friends, and they start training together. Along the way, they discover that they have some shared interests in combat techniques and a love for adventure. As time passes, they become close friends and perhaps something more as they face various threats to the school and their world.
In such a fanfiction, one possible plot could be that Ruby sacrifices herself to save her friends from a powerful and evil enemy. Maybe she uses her Silver - eyed Warrior powers to their fullest extent, which drains her life force but stops the enemy from harming her team. Her sacrifice could then inspire her friends to carry on her legacy and fight even harder against the forces of evil.
Well, it could be about the RWBY characters going on a mission in a space shuttle to explore a new planet. Maybe they encounter some alien Grimm or face challenges with the space shuttle's systems.
One possible plot could be that John Wick is somehow transported to the RWBY universe. He could team up with Team RWBY to take on a new and powerful enemy. Maybe a group of assassins from his world have also made their way into Remnant and are causing chaos. John Wick's combat skills would be a great asset to the team.
You can try fanfiction websites like Archive of Our Own (AO3). There are a large number of RWBY fanfictions there. Just search for 'We will rock you' in the RWBY section and you'll likely find some interesting ones.
One possible plot could be that the characters face a new, more powerful type of Grimm that has abilities they've never seen before. They have to quickly adapt and find new ways to fight. Maybe Ruby discovers a new form of her scythe's power to combat this threat.
Well, it could continue the character development of Jaune. Maybe he faces new challenges in the games that are even more difficult than before, like having to deal with stronger opponents or more complex game rules.
One possible plot could be that Ruby Rose somehow gets transported to Equestria. She might initially be confused by the magical and colorful world. The ponies could be both curious and a bit scared of her scythe and combat skills. Ruby could then team up with the Mane 6 to face a common threat that requires both her combat abilities and the ponies' magic. For example, a new kind of dark magic that is corrupting the land and only Ruby's speed and fighting skills along with the ponies' unique magics can stop it.