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You're missing the part when you can dump your current hand and get a new one immediately, and potentially do this multiple times without losing card advantage (beyond the first activation).
Invisible Stalker + Whispering Madness + Runechanter's Pike = Unblockable, Hexproof death machine.
I could see maybe Hellrider in Tibalt's deck. The others don't make much sense, as there are few Goblins in Innistrad.
I hope it's Sorin, Lord of Innistrad though. It would certainly help with my Esper Tokens deck. An alternate art Lingering Souls would be pretty cool too but I doubt they'll go...
I went 3-1 in two pre-release events with straight Rakdos. Stab Wound is just a Limited all-star. Removal or life loss for three mana is so good.
Rakdos Cackler is one of the better one drops in the entire set, as far as creatures go.