Shizuka, Twofold Virtuoso

: At the beginning of your postcombat main phase, you may activate one of Shizuka, Twofold Virtuoso's loyalty abilities for a second time this turn
+1: Tap target creature an opponent controls and exert it. If that creature is already tapped, you gain life equal to its power.
-1: Target creature an opponent controls gets -4/-0 until your next turn. If that creature blocked this turn, draw a card.