Of course there’s a False Ending, it’s Castlevania after all. Path to the True Ending in this game is slightly more obvious than in others, though. Or maybe I just played enough Castlevania’s by this point.
First, you obtain the spell the cures vampirism, and you even get to practice it on the monk shopkeeper. And then during battle with Loretta and her sister, you just distract them long enough to cast it.
I also beat them to get the False Ending. They aren’t hard. Funny thing is, the spell is called “Sanctuary”, so it’s not very obvious from its name that it cures vampirism. And I picked it up completely by chance, not evening remembering where.
By that time, I think developers ran out of budget, since they just dump 4 paintings (portals) on you, go and clear those, then come back.