"When you unlock this door, manifest dread. (You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.) <> Whenever you attack, target attacking creature gains double strike until end of turn. (You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)"