Bontu's Monument 
Legendary Artifact
Black creature spells you cast cost 
less to cast.
Whenever you cast a creature spell, each opponent loses 1 life and you gain 1 life.
Legality
standardNOT LEGALpioneerLEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL