Ezria, Benevolent Seraph

Flying
White creature spells you cast cost {w} less to cast.
This effect reduces only the amount of colored
mana you pay. (For example, if you cast a white
creature spell with mana cost {1}{w}{w}, it costs
{1}{w} to cast.)
Sacrifice Ezria, Benevolent Seraph: Creatures you
control gain indestructible until end of turn.