Ballroom Blitz

Creatures you control get +1/+1 and gain first strike and haste until end of turn
Creatures target opponent controls get -1/-1 until and of turn
"Laughter was all around, the smell of wine in the air, then things went suddenly silent and I looked around as some of the guests transformed into those hideous beasts and started tearing us to shreds."
-Werewolf attack survivor