Circle of Affliction 
Enchantment
As this enchantment enters, choose a color.
Whenever a source of the chosen color deals damage to you, you may pay . If you do, target player loses 1 life and you gain 1 life.
Legality
standardNOT LEGALpioneerNOT LEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL