The Blessed Curse

Curse {3}{b}, (If this spell is cast for its Curse cost target opponent looses 1 life for each creature with Undead or Undeath that you control instead of the normal effect)

You gain 1 life for each creature with Undead or Undeath that you control.
"Oh cursed one, may your soul wander in peace or in anger but either way you shall be free," Ashra, The Forgotten Queen.