Bones of Osoros

Bones of Osoros enters the battlefield tapped
unless you control six or more lands.
{t}, : Add one mana of any color to your mana
pool.
{w}{u}{b}{r}{g}, {t}: You may cast a nonland card
with converted mana cost 7 or lest from your
hand without paying its mana cost.
Within the lands of a dying empire, lie the bones of
their god