Prava, Priestess of Light

All creatures you control, other than Prava, have Vigilance
When one or more white creatures you control attacks, gain one life for each white creature attacking
While Prava, Priestess of Light is untapped, creatures your opponents control
cannot attack you or a plansewalker you control
unless they pay {1} for each creature
"A holy war cannot be won with faithless troops"
-Prava, Priestess of Light