Flora The Moon Presence

Flying, Menace. Before attacking, sacrifice X permanents you control. Moon Presence gets +X/+0 until end of turn. If Moon Presence would deal X damage to a player, they prevent that damage. Instead, they sacrifice X permanents. If they can't, they lose the game.

{t}{2} (using two different colored mana, no colorless): Target creature’s toughness becomes 1.

{t}{4} (using four different colored mana, no colorless): All creatures except Moon Presence have their toughness set to 1.