Really enjoyed this one. The idea behind the story is interesting and the demon plot's not bad either.
There's some excellent character development for both Jason and Richard, with one being exposed to magic for the first time and the other breaking his 'no magic' rule to rid himself of his family's bad karma. It's not the first time the action has revolved around the side effects of a spell but having Richard as the culprit is a great twist so top marks to the writers for this. As in all the best episodes, the main plot involves the whole cast (with the notable exception of Chris - any ideas?).
The special effects are great this week, particularly the cleansing spell, and the direction is strong for the whole hour. Not sure the possessed Phoebe storyline was really the right choice but it was entertaining and Alyssa is so good at playing the bad girl. I loved the way she wrecked the party by turning the food into frogs and I completely loved that Piper froze the room. They should do more stuff like this!
The swarm demons are good value. Yes, the idea of 'kill the king, kill them all' isn't new but who cares? It's fun watching them all blow up and I enjoyed seeing Phoebe channel their powers against them. I wish she would do this more often.
Given that karma is such a big part of the wiccan faith I'm surprised they've not done this story before. The threefold return is a well known rule of witchcraft (i.e. if you do something bad it'll come back on you three times harder) yet it's taken Brad and his mates six years to realise this.
For me, Richard is the star of the show. That gleam in his eye as he goes into his potion cupboard is Cole all over again. Be afraid. Be very afraid.