Yes, a popular one involves the Grimm from RWBY showing up in Skyrim. The Dragonborn has to team up with RWBY characters to fight them off. It combines the combat styles of both universes really well. The fanfic also delves into how the people of Skyrim react to the RWBY characters' unique abilities and appearances, which is quite engaging.
Another way is to check out RWBY or Skyrim related forums. There are often threads where fans share their favorite crossovers, and you might be able to find links to some great rwby skyrim crossover fanfictions. Also, Reddit can be a good place. There are subreddits dedicated to both RWBY and Skyrim, and sometimes fans post crossover fanfics there.
One idea could be that the Dragonborn is somehow transported to the RWBY world. They could use their shouts to combat the Grimm. For example, 'Fus Ro Dah' could send Grimm flying back, and the local Huntsmen and Huntresses are both amazed and a bit wary of this new power.
I think Ruby and the Dragonborn would be an interesting pairing. Ruby is young and full of energy, and the Dragonborn has a lot of power and experience. Ruby could learn a lot about different forms of combat from the Dragonborn, and the Dragonborn could be inspired by Ruby's positive attitude.
Maybe the RWBY characters are on a quest in Skyrim to find a way back home. Along the way, they meet various characters like the Dark Brotherhood or the Thieves Guild. Ruby might befriend a young Nord who is also an aspiring warrior and learn some of the local combat techniques. Weiss could use her knowledge of Atlesian technology to improve some of the weaponry in Skyrim. Blake could uncover some secrets about the Daedric Princes that are related to the Grimm in some way, and Yang could participate in the Skyrim's famous brawls and earn a reputation as a fierce fighter.
One great Skyrim crossover fanfiction is the one that crosses over with 'Lord of the Rings'. It combines the rich lore of Middle - earth with the magical world of Skyrim. The characters from both universes interact in interesting ways, like Aragorn teaming up with a Nord warrior to fight a common enemy. Another good one is the crossover with 'Game of Thrones'. It creates a whole new set of political intrigues and battles as the houses of Westeros get involved with the factions in Skyrim.
A common theme is the clash of different cultures. For example, when a character from a different universe enters Skyrim, they have to adapt to the Nordic culture. Another theme is the power struggle. If a powerful character from another franchise like a Sith Lord from Star Wars comes to Skyrim, there will be a power struggle with the local mages or warriors. And exploration is also a theme. Characters often explore the vast landscapes of Skyrim that are new to them.
One common theme is the combination of powers. For example, how the RWBY characters' unique abilities interact with the werewolf form in Skyrim. Another theme could be the exploration of new worlds. Since Skyrim has a vast and detailed world, fanfictions might focus on RWBY characters exploring this new environment as werewolves.
The Mask's influence on the RWBY world might also change the appearance of things. If Weiss were to encounter the Mask, it could transform the elegant and icy settings she's used to into something more zany. The ice sculptures in her family's manor could start dancing around like in a wacky cartoon. And the Grimm, the dark creatures in RWBY, might react in strange ways to the presence of the Mask - perhaps they would be both terrified and strangely attracted to it at the same time.
RWBY crossover RWBY fanfiction can enhance the universe by exploring new relationships. For example, characters who have never interacted much in the original series can form new bonds. This gives a deeper understanding of the characters' personalities. It can also expand on the lore. By mixing different elements from within the RWBY world, new aspects of the history, magic, and technology can be revealed.