One idea could be that Mario and his friends are transported to the RWBY world and they have to team up with the RWBY characters to fight a common enemy like a powerful Grimm that has some sort of connection to the Mushroom Kingdom's villains. Maybe Bowser has made a deal with this Grimm to take over both worlds.
Toad and Blake could form an alliance. Toad is small but mighty, and Blake is stealthy. They could work together in reconnaissance missions. Toad could use his speed to quickly gather information, and Blake could use her cat - like senses and stealth to move around undetected and protect Toad if they are discovered.
In the 'rwby tai vs raven fanfic', it might focus on the backstories that led them to this point of conflict. Tai might be fighting for the sake of his family or his ideals about protecting Remnant. Raven, on the other hand, could be in the fight for her own self - interest or to protect secrets she holds. The fanfic could also show how their relationship, whether it was once friendly or always strained, affects the way they fight each other.
One main theme is often cooperation. Since it involves two different groups of characters, they usually have to learn to work together despite their differences. For example, the RWBY characters with their unique semblances and the RVB characters with their military tactics need to combine their strengths.
The fanfic has also led to more discussions within the Mario fandom. Fans debate about the plausibility of the relationships and storylines in the 'bowsette and mario' fanfics. This kind of interaction keeps the fandom alive and engaged, as everyone has their own opinion on how the Mario universe can be expanded or re - imagined.
There might be a fanfic where the technology from RVB is introduced to the world of RWBY. Like, Caboose could accidentally bring some of the Freelancer's advanced weaponry to Remnant. This would cause a stir as the RWBY characters try to figure out how to use or counter this new technology. It could lead to some humorous moments as the RVB characters try to explain the functions in their own, often-confusing ways.
One great 'abrn vs rwby fanfic' is 'The Clash of Teams'. It has really exciting battles between the two teams. The characters' powers are well - portrayed and it keeps you on the edge of your seat.
A good way to find quality 'rvb vs rwby fanfic' is to follow the works of well - known fanfic authors in either the RVB or RWBY fandoms. If they have written crossovers before, chances are their 'rvb vs rwby' works will also be well - written. You can usually find lists of popular authors on the aforementioned fanfiction websites. Once you find an author you like, you can explore their other works as well.
There's also 'The Battle Beyond' which focuses more on the strategic aspects of the RWBY and RVB characters coming together. It shows how they use their unique abilities in combination to overcome challenges. It's a great read if you like to see how different power sets interact.