Unfortunately, it sounds to me like she may becoming mentally ill and/or is under some kind of cult-type influence from this leader. Vampire stories which I have never liked are really popular right now so it could be that she is really suggestible. In other words has trouble telling the difference between reality and books and movies, where some people turn into vampires.
If she is mentally ill, what she says such as a the dance instructor calling and yelling at her, and the strange priest giving her orders to be at church, cannot be taken at face value b/c it might reflect psychosis. In other words she might think that this happened but in reality it didn’t. Same thing for thinking the guy is controlling her. These could be persecutory delusions. OTOH, he could be some kind of bizarre person who is using these concepts and actions to control her. However unfortunately this looks to me like psychosis is a possibility. I have only your short summary to go on which is why I’m suggesting a referral to a priest who can listen to both the religious and the psychological issues. My suggestion is writing down as many of her symptoms, beliefs, actions and their time frame as accurately as possible before seeing him.
But this sounds like it could be serious and giving advice is beyond me. I would talk to a priest and maybe write down what she is saying and doing in as much detail as possible, so instead of just mentioning the vampire issue, you can say that she’s left phone messages and etc. There is a possibility of blessing/exorcism but unfortunately the issues of excessive control that this guy may have over her and possible mental illness may be relevant. You could try praying but I don’t know if she’s in a frame of mind to pray at this point. take care.
It sounds like she needs some serious help. whatever the truth is. You can’t compel her to get help but maybe a priest would suggest talking to her family and seeing if they have noticed what you have. Maybe start with a priest who does pastoral counseling and is used to seeing people with psychological problems. Best of luck to you.
You sound like you are a good friend. A lot of people would have just backed off when she started sounding strange. You don’t want to hurt yourself getting too much into her problems but if you get a consultation and it is suggested that you tell her family what is happening, they may be able to take some action. Keeping this quiet doesn’t sound good if the pattern is she’s getting worse, but I think expert advice is needed.
It is possible to recover from psychotic episodes, if that’s what this is, but prompt treatment really helps make that happen. If this is something else like a cult situation, I’m not qualified to comment on that.