... would she be tagged as "Saya_(blazblue)" too?

Y'know, coz they are the same person.

No, because that would be a spoiler.

You know, ruler of the NOL or not, she's still flippin' adorable like this.

NeoChaos said:

No, because that would be a spoiler.

So what happens when the big bad is never mentioned by name of title, only to later be revealed as [insert name of character here]. In these cases revealing their names would be a spoiler, but since they didn't have any other way of being referred to in the actual game/series/manga there really shouldn't be any way to tag them at all except for using their real name.

Why "mikado" and not "imperator" and why call her either, since she's not mikado or imperator anymore

Why not just call her by her actual name hades izanami since that doesn't really spoil anything about her character. It doesn't spoil any more than calling her mikado.

We have about 4 options for names for this character. 2 of them aren't accurate anymore. One is a spoiler. The other one will continue to be accurate probably until the end of the series her actual name.