Covenant of the Sign

When Covenant of the Sign enters the battlefield, choose a creature type. Creatures you control of
the chosen type get +1/+1 and have protection
from black and red.
At the beginning of your upkeep, you may pay {1}{w} and sacrifice a creature of the chosen type.
If you do, create a 2/2 white Angel creature token
with flying and vigilance.
This is my covenant with you and your descendants
after you, the covenant you are to keep - Gen 17:10