Lemonade Stand

Flying, trample At the beginning of your upkeep, sacrifice a creature other than this creature. If you can't, this creature deals 7 damage to you.

Flying If noncombat damage would be dealt to you, prevent that damage. You gain life equal to the damage prevented this way. When Purity is put into a graveyard from anywhere, shuffle it into its owner's library.

If you would gain life, you gain twice that much life instead.

At the beginning of each end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Whenever you gain life, target opponent loses that much life.