Indestructible (Effects that say "destroy" don't destroy that permanent. An indestructible creature can't be destroyed by damage.)
As long as your devotion to green (Each in the mana costs of permanents you control counts towards your devotion to green.) is less than five, Nylea isn't a creature.
Other creatures you control have trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.).
: Target creature gets +2/+2 until end of turn.