One idea could be a joint quest where the Mighty Nein and Vox Machina have to team up to defeat a powerful, ancient evil that threatens both their worlds. Maybe it starts with some strange magical disturbances that draw the attention of both groups.
Another plot point could revolve around a common enemy. A powerful villain might emerge that neither group can defeat alone. So, they are forced to team up. This would require them to put aside their differences and work together. There could be moments of tension as they struggle to coordinate their strategies, but in the end, they learn from each other and become stronger as a combined force.
The fanfiction might focus on the world - building aspect. Since both Mighty Nein and Vox Machina exist in the same universe in the Critical Role world. The meeting could expand on the existing lore. Maybe they discover new places or secrets together. For instance, they could stumble upon an ancient ruin that neither group knew about before. This could introduce new magical items or threats that they have to face. It could also show how the two groups' different relationships with various factions in the world play out when they are together.
A possible plotline could be a joint quest to defeat a powerful and ancient evil that neither group could handle alone. This would force them to pool their resources and skills.
Grog from Vox Machina and Fjord from the Mighty Nein. Grog is this big, brawny warrior and Fjord is a half - orc who is more reserved and still exploring his powers. Grog could be a bit of a mentor figure to Fjord in terms of physical combat, while Fjord could teach Grog some things about strategy and using his strength in a more calculated way.
Percy from Vox Machina is often quite popular. His complex backstory, his skills with guns and his noble yet flawed personality make him stand out. In the fanfiction, his interactions with the members of The Mighty Nein can be really engaging, especially when it comes to discussions about technology and magic.
One interesting plot idea could be exploring the backstories of the less - known characters in more depth. For example, delving into the early life of Pike and how she came to be a cleric.
One interesting plot point is the power exchange. For example, in some fanfics, Naruto's jutsu are used by Vox Machina members, creating unique combat scenarios. Another is the culture clash. Naruto's shinobi culture meeting Vox Machina's more medieval - like fantasy culture can lead to some humorous and thought - provoking moments.
One interesting plot idea could be a crossover with another popular anime where the characters from Birdy the Mighty Decode have to team up with the new characters to face a common enemy. For example, if they cross over with Naruto, Birdy and her allies could join forces with Naruto and his friends to battle a powerful alien threat that is too much for either group alone.
Maybe a crossover with a fantasy - themed cartoon. The Mighty Ducks enter a magical world where they have to use their hockey skills in a whole new way. For example, they might play hockey on floating ice rinks in a land of wizards and dragons. They could also team up with the local characters to defeat a common enemy that threatens both their worlds.
One idea could be to crossover Birdy with a popular mecha anime. Picture Birdy in a Gundam-like universe, fighting side by side with giant robots. Another could be a crossover with a magical girl anime, where Birdy has to learn some new magical powers to save the day. Or perhaps a crossover with a detective anime, and Birdy uses her skills to solve complex mysteries in a new setting.