It's time to admit that season 3 has been nothing but a bitter disappointment, and there's no hope for improvement. Besides, I suspect Murphy is too occupied with The Normal Heart for HBO to pay enough attention to the series he's seemingly already bored with.
This week we (and Fiona) finally learn Marie's secret: she sold her soul to a French speaking and cocaine sniffing Rob Zombie look-alike - Papa Legba in exchange for everlasting life. On top of her soul she promised him a favour every year, which she thought was nothing more than friendship with benefits, but he had no interest in sex (figures). The first year he's asked for Marie's own newborn, further on she had to look for somebody else's babies. Every time she feels like the baby's hers, so the price is not that low.
Inspired by the story, Fiona tries to cut a deal with Papa, sadly, turns out she has no soul to trade. So she decides to kill every young witch in the coven, 'cause it's impossible to say who the Supreme-to-be is: they all seem growing stronger. Well, except for poor Cordelia.
Not only she seems to have lost all her magic powers, but is devastated by Marie's confession of hiring Hank, who she (Delia) learns was a professional witch hunter. Fiona, like most mothers in her position, puts the blame on her daughter and even slaps her. She refuses to accept Delia's help when performing a ritual to take the Corporation's money and basically implies her daughter is a complete failure. Auntie Myrtle confirms her words by suggesting Delia to become a cruise hostess or start a small salad dressing production line. I now believe Cordelia is the next Supreme.
The series characters though still bet on Misty, Fiona even arranges a private Stevie Nicks concert for her (I'm not a fan, so...). All of this upsets Madison-The-Attention-Whore, so to pay back for her own resurrection she has Misty buried alive.
Nan also uses her newly discovered mind control gift for evil: she forces Luke's mom to drink a bottle of bleach as an act of retribution for what she's done to her son. Well, as Fiona says later in the show, the bitch had it coming.
Unfortunately, the new power was insufficient to protect her from Marie and Fiona, who decided to give her soul to Papa instead of an infant Marie stole from the hospital. Though Nan was not that innocent after the murder she's committed, Papa settled for her soul and took it some place dark, supposedly, hell.
I guess now it comes to how all/the majority of characters die. too bad I don't feel a thing when it happens.