Halo of Twilight 

Enchantment
Reveal each card that you draw.
Whenever you draw a land card, you gain 3 life.
Whenever you draw a nonland card, each opponent loses 1 life.
I really wanted it to be "target opponent loses 3 life" to mirror the first ability, but the fact that life loss is obviously much more powerul coupled with the fact that you'll probably be drawing more nonlands than lands made me lower it. To compensate, I let it hit every opponent.