In VT1 there was last stand.It was ok,but it usually came down to standing in one area with 2 people blocking/pushing and 2 shooting,swinging. It had swarms come in waves and occasional specials. Rats were getting stronger the more waves you killed. Like I said,it was alright, but combat was pretty boring and you had to do a 40 minute stand to get to a point where the waves started to be interesting.
Now,I propose an arena mode(most likely a mod when modding support is out) - set number of enemies, depending on difficulty, with a steady flow of specials. Maybe a boss spawn + specials when you clear the initial enemies.
150 trash, 6 chaos warriors,10 stormvermin,5 shield stormvermin,15 marauders,6 berserkers - for champion,
200 trash, 12 chaos warriors, 18 stormvermin, 10 shield stormvermin,30 marauders, 12 berserkers for legend.
all in a BIG(twice as big as righteous stand elevator arena) arena with obstacles etc. with supplies scattered in random places.