­Lust for the Hunt had this problem where it was a sorcery but felt like an instant. This is another sorcery pitch card... but I think this one is okay. Global wipes are so often sorceries, that I don't think people will think to use this as a combat trick, in the same way that LftH tried to.

Thinking about this as a instant, however, forces me to compare it to Fireblast. I don't think it's the same level of powerful, since Fireblast asked you to sacrifice a resource you were already using to finish the game. But, to be honest, discarding a single mountain ain't too hard. I don't know. I never saw one, but there must have been enough floating around, and no one complained...