Unicron the Boundless

Changeling (This card is every creature type.)
As Unicron enters the battlefield, choose a creature type. Spells of the chosen type you cast cost {w}{u}{b}{r}{g} less to cast. This effect reduces only the amount of colored mana you pay.
Other creatures you control of the chosen type get +1/+1.

"For a time I considered sparing your wretched little planet, Cybertron... but now... you shall witness... ITS DISMEMBERMENT!"