Strength in the Darkness

Strength in the Darkness may enchant only an untapped wizard with power 3 or greater.
Enchanted creature has, "{t}: Untap all lands you control. Gain 5 Life. Target opponent who
controls a black permanent loses 5 Life and sacrifices black creatures he or she controls until
the total power of all creatures sacrificed in this
way is at least 5. Exile Strength in the Darkness,
then this creature phases out."