Duskmourn: House of Horror

Leyline of Mutation | Enchantment | | If Leyline of Mutation is in your opening hand, you may begin the game with it on the battlefield. You may pay {W}{U}{B}{R}{G} rather than pay the mana cost for spells that you cast. | Sergey Glushakov

Roaring Furnace // Steaming Sauna | Enchantment // Enchantment | Room // Room | (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.) When you unlock this door, this Room deals damage equal to the number of cards in your hand to target creature an opponent controls. // (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.) You have no maximum hand size. At the beginning of your end step, draw a card. | Miklós Ligeti

Smoky Lounge // Misty Salon | Enchantment // Enchantment | Room // Room | (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.) At the beginning of your first main phase, add {R}{R}. Spend this mana only to cast Room spells and unlock doors. // (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.) When you unlock this door, create an X/X blue Spirit creature token with flying, where X is the number of unlocked doors among Rooms you control. | Marco Gorlei