Hullbreaker Horror has to be the largest instance of the Magic monkey's paw curling, right? We didn't want Alrund's Epiphany decks to dominate, and I suppose we got our wish. Now it's Hullbreaker Horror's world and we're just living in it.
The single solitary bright side is that it bodes well for black decks with Infernal Grasp. Aggression, card advantage, and spot removal can stop the Hullbreaker Horror decks from gaining any traction and they have very little they can do about it. I imagine that could change with some deckbuilding choices, but for now, black decks are viable again. Of the various options, I am very into Rakdos Vampires at the moment.
Why? Voldaren Epicure changed everything.