Sphinx Sovereign 
Artifact Creature — Sphinx
Flying At the beginning of your end step, you gain 3 life if this creature is untapped. Otherwise, each opponent loses 3 life.
Legality
standardNOT LEGALpioneerNOT LEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL