An Johnny version of a vampire, but how does it stack up against other creatures like it? Here's the latest Dark Ascension card, first spoiled by Robot Viking:
Solid card in draft, morbid enabler, and all around casual fun. To put things in perspective, colors aside, I think Murder of Crows is a better card than this. I'm also the guy that thinks Murder of Crows is better than Sturmgeist and would pick the crows over Sturmgeist in a draft if they were in the same pack, so I don't know how much you value my opinion on these matters. But if I had to choose between Fiend of the Shadows and Murder of Crows, the casual player in me would construct a deck with the fiend over the shadow any day. There's just so much more going on.
Much like Havengul Lich, I love any excuse to run four copies of Shimmering Grotto or any other rainbow land in the *hope* that it *might* become useful during the course of a game.
For Innistrad Block, I don't see this getting that much play. Vampire Decks usually want to be aggro and the 5cc slot is already filled with a more efficient beater name Falkenrath Marauders. The only exception that I could see is some type of Black/White human deck that starts off with cheap humans and then closes the game with cards like Fiend of the Shadows and Ravengous Demons.
When I look at this card, my mind goes to Legacy and reminds me of one of my all-time favorite mana producing artifacts: Fellwar Stone
In the history of Magic, there have been many different cards that have effects that allow you to play cards from your opponent's deck. Whenever I come across one of those cards, Fellwar Stone keeps calling me back. As for potential human stock to feed her bloodlust, I'd go for the obvious in Doomed Traveler and Skirsdag High Priest and go from there.
It would have been nice if Fiend of Shadows got a +1/+1 counter for every human sacrificed, but I guess you can't have everything.