Heavy Fog 
Instant
Cast this spell only during the declare attackers step and only if you've been attacked this step. Prevent all damage that would be dealt to you this turn by attacking creatures.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyLEGALvintageLEGALcommanderLEGAL