Sol'kanar the Swamp King 
Legendary Creature — Demon
Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.) Whenever a player casts a black spell, you gain 1 life.
Legality
standardNOT LEGALpioneerNOT LEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL