Gwendolyn, Yavimayan Hero

Whenever Gwendolyn, Yavimayan Hero becomes tapped or untapped, put a +1/+1 counter on it.
Vigilance, reach
{g}, {t}, Exert Gwendolyn, Yavimayan Hero: It
deals damage equal to the amount of +1/+1
counters on it to target creature or planeswalker.
(An exerted creature won't untap during your next
untap step.)