Seeing how she has officially been confirmed in the game as of Lostbelt 3, I would suggest we start re-tagging all of the koyanskaya posts where she's wearing the extreme cut dress as tamamo_vichy.
Or maybe alias koyanskaya to tamamo_vitch? I don't know if there's any "spoiler cooldown" for such occasions, but I think this can be done now. (But not tamamo_(assassin), since we still don't know if she's actually the same character)
It's pretty clear Tamamo assassin is also Vitchy, they have the same glasses, hair do and ribbons, as well as wearing basically the same amount of clothing. It's not official, but it's pretty official with all the context clues.
