Prevent dead allies from respawning past boss barriers.
If Rat Ogre and Stormfiend were the only bosses, it would matter less, but the resilience of the bile troll and unpredictability(and almost total lack of telegraphing due to erratic action intervals) of chaos spawn make them too unrealistic and unfun to fight alone. As it stands, careers with high damage are the only ones who can even realistically take them down alone(without the assistance of things like ammo boxes) because they simply heal too much(particularly true with meleeing them to death).