Galactus, A Myth Foretold

Flash, Flying, Shroud
Mutant creatures you control get +3/+3
Human creatures you control get +3/+3
Reveal Galactus, A Myth Foretold from your hand as part of the casting cost for any other
spell you control.
When you reveal Galactus, A Myth Foretold from your hand reduce the casting cost
of your next spell by {3}.