↓ Me talking below the cut because I'm super normal about them ↓
Nightshade (she/her), Night for short, is Varin's Corviknight. Snap (she/they) is Akki's Hydreigon. Akki and Varin are together all the time anyway so it works out. Spoilers but Akki ends up trading Snap to Varin so it double works out. They're amazing double battle partners, so they destroy in team-up battles with their two trainers, but this ends up being the reason Akki trades Snap to Varin. Snap isn't unhappy but she's a bit of a misfit on Akki's team anyway. And Varin is super into double battles.
Night is confident and charming, and she has kind of a "the popular girl at school" personality. She's generally widely liked and has a broad influence over the pokémon she knows. She's considered the glue that holds her team together. I'd imagine her sounding and acting like Grace from Inf1nity Train, to an extent of course.
Snap is a bit of an outcast in her own team. She's not disliked, and it's not that they don't get along well, but she doesn't really mesh well with their dynamic. They're all very bold, outgoing pokémon for the most part, and she's more reserved and prefers a quiet environment with one-on-one conversation. This meshes great with Varin's team, which is made up of a lot of friendly, but quieter and more reserved pokémon. I'd imagine her sounding like Norma from D3ad End: Paranormal Park.
In my fanon Hydreigons' puppet hands are semi-conscious. The pokédex states that they're not conscious, but it feels weird that Zweilous evolves a second head and then it just goes away upon final evolution. (I have a whole thing about how the pokédex seems like a bunch of urban legends and how the accuracy seems to vary depending on who wrote it, but I'll spare you that rant.) This is kinda where the "they" in Snap's she/they comes from. Like Snap would be a she/they regardless but sometimes "they" is more applicable because the hands are kinda alive. They'd probably be a bit single-minded and wouldn't be able to talk, but they do have a mind of their own.
Another fanon thing: Snap has the spots Deinos have in their little manes. While keeping pre-evolution traits isn't necessarily a red flag, it can be a sign of a pokémon who was overtrained and forced to evolve early. Sometimes they just keep their markings! Pokémon are very variable in pattern and such in my fanon. But sometimes it can be a sign of an early evolution. If or not this is the case with Snap I will not say, but I will say that neither Akki nor Varin would knowingly do this.
In the games, some trainers have pokémon who are fully evolved despite their level being too low. Like Ghetsis, he has a Hydreigon at level 54. Ten whole levels under the evolution level. This was thought up as a bit of an explanation for that. Early evolution isn't always an abusive and stressful thing when done right, but it's likely to shorten the lifespan of the pokémon, kinda like power feeding a snake. So it's still generally unethical. Some trainers know how to do it right, like gym leaders, but it's typically considered too risky to do and most trainers wouldn't do it anyway.
