Kruphix of the Mana Storm

Indestructible
As long as your devotion to green and blue is less
than seven, Kruphix isn't a creature.
Whenever you cast a spell that adds mana to your
mana pool, copy it for each spell cast before it
this turn.
He sucks up the mana of Theros, waiting for the time
to unleash his storm to protect his world.