Sniping Arrow is similar to Pierce the Pain, both require 2 energy to be used, but Decidueye's Ex causes 100 damage, and Decidueye (EC) causes only 70 damage and requires two Grass Energy
That being said, however, theres no harm in having even more of it
Stable, with the usual modern-set pattern
Anytime this kitty attacks, each creature you control with a power larger than its base power gets +1/+1 counters equal to the difference
Ghalta, Stampede Tyrant on ETB let us put all creatures from our hand onto the battlefield
Even if Dream dies a split second later, so long as he gets the "Free the End" achievement beforehand he wins