Tara introduces the reformed Marmy to the six miles of bullshit that is Antonia Gavilán de Logroño -- "I died at the hands of vampires in the year 1610! Our brave and loyal friend Marnie has summoned me from across the centuries! For we are once again at war!" -- and they all kind of chew on that for awhile.
There's a funny implicit thing about this storyline which never say aloud, but all the actors are clearly in on, where you would have to ask yourself whether this is just Marnie being Marnie. Did a switch finally flip in her head and she's Sally Field now, or is she being dramatic and witchy, or can they assume from all the magical shit she's been pulling that this is true? You could watch this whole show with the viewpoint that Antonia never existed, and it wouldn't really change much: Even the scene where Marnie X'd herself to get Antonia back could, in that construction, just be a symptom of her spiritual suicide whether ghosts exist or not. I mean, most religion and all magic come from the understanding that it doesn't matter -- that there's no meaningful distinction to be made between inner truth and outer fact, and that getting confused about that results in the madness of both Dawkins and Falwell -- but as a viewer it's an interesting meta-game to play.
Some folks leave, and Antonia wishes them well -- after all, if they're gonna lose their nerve, they'll get what Katie had coming -- and gives a great big speech about how the vampires are coming, they've fucked with at least two of them and it's practically useless at this point to point any fingers about it.
One thing that is beautiful about Antonia is her Christianity, which I get is confusing, but makes a lot of sense once you realize that, 400 years ago, there weren't witches. They were just called women. In the same way that bisexuality is a "phase" for women and damnation for men in our modern world, women's spirituality was beside the point for so long that you could act just like a witch, but as long as you did it in the red tent and kept that hair covered up, you still belonged to the Christian world. (At least up until the New World, when suddenly they decided that women's sexuality and spirituality were some interchangeably terrifying thing, and we're still dealing with the fallout from that one.)
So Antonia is taking a firm Christian tack that you might overlook if you try to connect her spirituality or intentions with Wicca, because she's not one of those. (She doesn't even really seem to have a concept of what witchcraft means to Marnie and the others, because she doesn't need the distinction between God and Goddess to prove her point that we do in the present day.) She is carrying out evangelical spiritual warfare, in God's and Descartes' name: