Morophon, the Boundless

Changeling (this creature is every creature type.)
As Morophon, the Boundless 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.