1. Set the trigger to Side Not Present, where Side is the side of the enemy (East, West, or Resistance)
2. Group the trigger to the player, and set it to Whole Group Present.
-Pilot
EDIT:
Correction in #2
EDIT2:
Oh yeah, be sure to make all the tiggers an ending trigger of some sort.
EDIT3:
Ahhh, where are my manners? Welcome to the OFPEC Forums!