MTG Commander Masters Morophon, the Boundless (Borderless)

Changeling (This card is every creature type.) As Morophon, the Boundless enters, 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.