You can tag each enemy to the same which would mean you have to kill them all for an action to happen. Or you can even make each enemy have its own action making it spawn different waves for each kill. It is possible for sure if you want it so you have to kill a wave to spawn another, just tag all the enemies in the wave the same way.
I kind of finished it as a full map in 5 hours that would be a record for me xD. Need to go back and straighten/more detail up some but I think there is some very interesting peaks as it already gives a run at my best Doom 64 ex map yet. It was started because I was making a showcase map how to do somethings on Doom 64 ex. But it quickly took form into a decent map here! Anyways, this showcases a switch, how to spawn monsters by killing a monster, how to call actions in general when killing a monster, tagging barrels exploded to a door (secret), several monsters tagged to a single action (kill all the monsters in the room to spawn a second set), and even more.
Any Doom guys know what's going on here??