My opponent was in a bind. He had a handful of good cards but no evil, and only one in his territory. So he activated Burial Shroud to keep me from attacking him (since he had insufficient blockers) for two turns in a row, but took his rescue attempts as normal. First, is that the way the card is supposed to work, or if you prohibit opponent from attacking you,do you have to also bite the bullet and not attack him on your turn? In either case, what happens to the card after it's used twice? Is it discarded? banished? Deactivated and useless?