Yeah, maybe. If her Dark ver. confirmed as separate character. If not, better stick with just Kokanskaya (fate)
Lore wise as I understand it, it goes something like,
From the start of Lostbelts part of the story, there was just "Koyanskaya". Then when she was defeated as Beast IV, she split into two fragments, "Koyanskaya of Light" and "Koyanskaya of Darkness".
So I don't really know if it's worth making two new tags and going back to re-tag all the Koyanskayas, or just lumping it all under Koyanskaya (Fate)because it's two parts of the same character.