Is Yukari and Okina sisters?

[Drake]

"Kishin" is just written 鬼神 which is literally "oni god", not that it actually means they're a god. Note in the context of Touhou it's also typically "鬼神長", a title used so far exclusively to mean certain oni that command others and are hired as hitmen for the Ministry, so there's no real reason to believe they're even a subspecies of oni.

[PK]

That makes sense, although i swear someone here once said they were a class of gods.
Also, in one of Marisa's MoF endings Nitori tells her that Youkai Mountain belonged to a "鬼神様", and when that oni left all their faith was gone with them too.
If they had faith they were a god, no? Although maybe it was just that particular one who managed to become a deity?

[Drake]

I don't have an answer for that. I'm not even sure what that phrase is referring to really, since her conclusion is just "now it's more boring" (with the oni gone? With a god gone? Doesn't seem all that clear). I'm not sure if a specific "鬼神様" is ever referred to anywhere else, even though yes the oni did control the mountain previously.

[BlahaIsAFraud]

i always thought okina was kind of a clone of Yukari, and Eternity is a clone of Wriggle.