The New World Covenant

Whenever an artifact enters the battlefield or a nonartifact permanent becomes an artifact you may put a charge counter on target artifact.
At the beginning of your upkeep you may pay {w}{w} or {u}{u}. If you pay white, create a 0/2 colorless Home artifact creature with defender. If
you pay blue you may exile a home permanent you control, then search your library for an artifact with a converted mana cost equal to the number of charge coun