Mercurial Geists 
Creature — Spirit
Flying Whenever you cast an instant or sorcery spell, this creature gets +3/+0 until end of turn.
Legality
standardNOT LEGALpioneerLEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL
Creature — Spirit
Flying Whenever you cast an instant or sorcery spell, this creature gets +3/+0 until end of turn.