Hallar, the Forestfletcher

First Strike, Reach
Whenever a player casts a spell with flying put a +1/+1 counter on Hallar, the Forestfletcher, then Hallar deals X damage to up to X target creatures with flying where X is the number of +1/+1 counters on Hallar, the Forestfletcher.
"I used to be the archer of fire, but after my injury all I can do is take to the canopy."