Dawnhart Wardens 
Creature — Human Warlock
Vigilance Coven — At the beginning of combat on your turn, if you control three or more creatures with different powers, creatures you control get +1/+0 until end of turn.
Legality
standardNOT LEGALpioneerLEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL