Exploit to Oblivion

Sacrifice any number of creatures you control,
each opponent loses life equal to the number of
creatures sacrificed this way.
Add {b} mana to your mana pool for each creature
that entered the graveyard this turn.
Innestra despised the angels for helping the humans
after their countless incursions, so instead of fighting
for their freedom as she had for every other species of
Falarnia, She sentenced them to a life worse than
death, Mana draining.