Raava, Spirit of Life's Avatar

Possession —Whenever this creature enters the battlefield, exile it attached to another target
creature you both own and control as an aura
with a power of 2 or less.
Possessed creature gets +4/+4 and gains prowess,
first strike, haste, and trample.
"The spirit of the Avatar lives through me. Do not be
afraid. You have light on your side."