Valnok, the Never-Fallen

Whenever Valnok, the Never-Fallen enters the battlefield or becomes monstrous, choose one
that hasn't been chosen -
-Put X +1/+1 counters on Valnok.
-Tap X target creatures you don't control.
-Valnok deals X damage to target creature or planeswalker.
{x}{x}{g}{u}{r}: Monstrosity X. (f this creature isn't monstrous, put X +1/+1 counters on it and it
becomes monstrous.)