Rastakhan's Rumble Guide
A mind is a terrible thing to waste. It's far too delicious.
If I wanted to lose on turn 5, I'd play constructed
This dude is a cheap whore. I got him on the 4th battle when you only have 25 HP. His hero power halved my HP on turn 2, then he used Spreading Madness on turn 3 and hit me twice with that. Then he double mind blasted me on turn 4 for the kill. His minions never hit me once. If he gets double mind blast in his starting hand, consider it a loss, regardless of your skill level. That's ridiculous.
You must be mistaken on the turn that happened, his hero power costs 4, and he doesn't start with extra mana like some of the other bosses.