There's been some back-and-forth speculation for a while now that Resident Evil Village could be stepping out of the mad science body horror of its running canon and doing an occult horror instead.
If they do play an occult horror straight, there's no telling how things will end. They might drop the monstrous transformation trend in favor of something like a superhuman awakening where it's just her but stronger and faster, or maybe something like a "villain and dragon" type encounter like the fight with Stefano during Evil Within 2.
The idea of a Castlevania-like thing also does kind of have a nice ring too. Dracula has turned into a ton of weird stuff throughout the run of that series and been employer to all kinds of dread monster girls like Scylla, Amphisbaena, and whatever the heck that crystal thing was in Lords of Shadow. There's certainly no shortage of ideas for gruesome gothic-themed monsters there.
It is kind of hard to imagine that mad science isn't involved somewhere that leads the tall lady to some horrible end though.
I just reached the moment where she transforms into... Something I clearly didn't expected at all. It remind me of both Salazar and Simmons in RE6 for some reasons.