Already, Thing in the Ice and his enormous flipside is being called a control finisher. It’s not hard to see how. Not much can deal with a 7 / 8, especially one that evacuates all other non-Horror creatures from the board. The non-Horror clause is a big deal since you can have multiple copies of Thing in the Ice on the board at once. It’s hard to say what other playable Horrors will be in Standard along with it. The only notable one outside of the new Innistrad sets is Despoiler of Souls from Magic Origins. But a 3/1 that can’t block isn’t really a big deal if it’s on the other side of the board; but it feels good to have them on your side of the board in this case.
Awoken Horror may prove to be good in Modern, also. Spellskite is a popular Horror played in the format. To a lesser extent, Phyrexian Revoker and Phyrexian Obliterator look pretty good alongside it. Some players think it may creep into Legacy and even Vintage. It’s only 2 mana (1U) and those formats have cheaper and powerful instants and sorceries than you’ll find in Standard.
The Horror theme is alive and well in Shadows Over Innistrad. Not only does this card have great flavor, but this may be one of the best cards in the entire set.