Lightbearer Nun

Flash, Warded from Black (Black sources cannot
damage the creature.)
When Lightbearer Nun enters play, target
creature gains +2/+2, Warded from Black,
until the end of turn.
When a Black creature comes into play under an
opponent's control, you may pay {2}{w} to return
Lightbearer Nun to your hand.
"One True Light banishes all darkness."