Warden of the First Tree

{1}{W/B}: This creature becomes a Human Warrior with base power and toughness 3/3.
{2}{W/B}{W/B}: If this creature is a Warrior, it becomes a Human Spirit Warrior with trample and lifelink.
{3}{W/B}{W/B}{W/B}: If this creature is a Spirit, put five +1/+1 counters on it.