Frostnova, Pure Winter

At the beginning of your turn, tap 2 target creatures or give 2 target creatures a stun counter. Whenever an opponents creature taps, deal 1 damage to that creature. Whenever a creature you control taps, draw a card and add one mana of any color to the mana pool. At any endstep, all creatures you don’t control that are tapped take 1 damage.