Benviesna, Wings of War

Flying, Battle Cry (Whenever this creature attacks,
each other attacking creature gets +1/+0 until end of
turn.)
Untap target creature and each other creature that shares a color with it. Those creatures get +2/+0
until end of turn.
Benviesna, Wings of War gets +3/+3 for each opponent whose life total is less than half their starting life total.