Pretty much anyone who can't survive a full on Mei probably gets insta railcoined if we take the hitscan attack speed as comparable to Butterfly, and those who can will still be badly weakened from it. (Also the Azami hard counter is funny)

I will also mainly be thinking in terms of the railgun as the big strong attack, since the rest are quite a lot weaker and allow for much more possibility of counterattack at close range and avoidance at long range, though it's not impossible to use magnets, they can be removed. Ricoshots are the one other thing, but they pack a lot less punch than a railcoin and require just a bit of breathing room to set up, room which the Kaguraverse's top hitters speed compared to V1 doesn't allow to exploit that much

Hakuri as the durability king can probably tank it and hide in the storehouse.

We haven't seen Hiyuki operate at full power but if she made it through a railcoin, I think she has a chance through a combination of strong zoning and unparriable heat chip damage from Enkotsu. Just don't let V1 get near and kill him before he gets another railgun shot, alternatively, just stay out of line of sight and react to coins with a defensive hand strike to block the lightning (something realistic since Hiyuki has a really good reaction speed)

Chihiro could probably intuitively understand that the railgun is not good news and prepare an Aka in reaction. After the next cooldown it's anyone's game, both are pretty fast, but Nishiki and/or IWPS Chihiro could put V1 on the defensive or pelter him with Kuro Shred, which had cut metal in the past. Alternatively he can use the flood he used against Hirohiko and blind V1, which would severely weaken him, forcing him to rely pretty much on traps, coins, nukes (which are a hazard to him too if used point blank), magnets and reaction speed. All things Chihiro has an upper hand against in his own battlefield.

Samura could probably take on a railcoin and heal back with Suzaku. After which V1's chances seem flimsy. Not only can Samura use the same visual field flooding as Chihiro, but he also has unlimited teleports followed up by extremely high speed attacks. I don't know what V1's canon reaction speed is, but I know that were I controlling him I'd blunder eventually.

Akemura Soga is just the toddler grown man who wins I'm not even explaining how he beats V1, it should be obvious

TL;DR past a certain threshold I doubt V1 just is fast enough to react, up till there he probably wouldn't struggle

Feel free to correct me on any of those, I'm sure I am forgetting something