Seikatsu, Spirit of Life

Flying, Lifelink, Forestwalk
When Seikatsu enters the battlefield, return each creature card with power less than Seikatsu's toughness from your graveyard to the battlefield.
Seikatsu's toughness is equal to the number of creatures on the battlefield.
Whenever a creature enters the battlefield under
an opponents control, Seikatsu fights up to one
target creature with lesser converted mana cost.