If I remember correctly, this guest still has control, even if it is minimal. For example, she did not allow Su Luxia to see all her memories immediately, such as the artifact, while as soon as she achieved her primary purpose (to knock down her opponent Olinor) she allowed her to see everything she needed. Maybe because being an ancient vampire it's much more powerful and resistant to death (which didn't happen, by the way, since Su Luxia replaced it before it happened).
So I think it was just replaced for the amount of time it took to fix the "system of revenge against a**holes". while it fell into a deep sleep.
And now that the host is gone, thanks to the chalice is able to return. Probably with all the memories of Su Luxia still present, so knowing what happened and who Xavier is. . .
At least I hope so.
@The
CG
I'm talking shortsighted.
Myopia - or astigmatism - are not eye defects comparable to diseases. The eye simply has that shape, either slightly elongated for myopia, or slightly squashed for astigmatism, and therefore sees less from a distance or close up. But it is not a real fault, just as it is not a fault to be more or less tall or to have more or less wide shoulders. So being a vampire or not would have nothing to correct, because it does not change the shape of your eye