The reason I use Exsanguinate

At the beginning of each end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Each opponent loses X life. You gain life equal to the life lost this way.

Extort (Whenever you cast a spell, you may pay . If you do, each opponent loses 1 life and you gain that much life.) Whenever you tap a Swamp for mana, add an additional .