These cards must have been exposed to some sort of extreme conditions to have bent in the way they did
People generally feel, if they had a chance to compete in the game, or to at least break up the combo, it's OK
Basically, they wanted the full breadth of what the Marvel universe has to offer to be showcased
Once the current cards have all been drafted, players repeat the process by opening another booster pack each, drafting cards one at a time and passing the rest to their neighbour
In casual duels, it certainly can dominate quite ably, with the exiling of cards from the library being a more efficient method of milling, since they can't come back with reanimation or give someone threshold
The only promos I have purchased are these Wurmcoil Engines