I don't really understood the point of Rafaam. I think I've played him twice in my most recent 20 games, and won with him one of those times. Playing him means you lose a lot of important cards, and you end up playing one fatty a round after that. Whoo-hoo. If you play with Anubisath Warbringer, you'll lose your buffs. Rafaam is not good against any meta decks; maybe he was good against Bomb Warrior, but that's gone now.
The point of Rafaam is that you can use your hero power to get free legendaries (so you can play more than one per turn) as well as get rid of the corrupted bloods. You're never "forced" to play Rafaam, you use him late game to transform cards that won't matter much in the end game into potential threats. The problem is that you risk getting even more useless cards... But it is fun when it works - I once won againt Shirvalla Paladin because I got two Nozaris :)
It's a fun deck for sure, and it has a fighting chance against most meta decks, but you're pretty much never favoured to win :) I've played a lot with the deck, and you need to be ready to lose a lot. But if you already have a couple of meta decks and are looking for a fun meme deck, then plot twist warlock is a great choice. Keep in mind, though, that both Dorian (which is IMO a must for this deck) and Godfrey will rotate next April.