Olagartan, endless Cycle

As long as your devotion to blue, black or green,
is 7 or more, you may cast one creature card
from your graveyard, each turn.
Olagartan, endless Cycle costs {1} less to cast,
for each creature card in your graveyard.
Creature spells you cast from your graveyard,
cost {1} less, for each different card type in your
graveyard.