Domina, Banished Firebrand

Hexproof, vigilance
At the beginning of combat on your turn, you
may exile an instant or sorcery card from your
hand or graveyard. If a card is exiled this way,
you gain X life and Domina, Banished Firebrand
has +X/+X until end of turn, where X is equal
to the exiled card's converted mana cost.
To test their faith, God wrested one final possession
from His followers: The power He gave them.