I know Boxer Briefs, but this is my first Boxers Bird.
I'm ready to subscribe to the "reincarnated into every reincarnation novel I've ever read, chopped up and pasted together into a mess of clichés and pointless plotlines" theory. Hilarious.
I guess my theory is:
Previous Elena summoned the Devil and offered her soul to get her wish, which is why current FL is in possession of her body.
The Devil is inhabiting Klaus' body (thus his interest in her, since he has her OG soul).