Thiara, Lady of Souls

+1: Each opponent discards a card, create a Soul Coin Token (It's an artifact with "Tap, sacrifice this artifact: add one mana of any color.")
-4: Sacrifice a Soul Coin: destroy target permanent and Thiara, Lady of Souls deals damage to target opponent equal to its converted mana cost
-7: Destroy all creatures target opponent controls. Create a number of Soul Coin Tokens equal to the number of creatures destroyed