You can also turn the valves in the final boss fight to douse the boss with acid, and on dominating each valve takes 1/3rd of his health. It only hurts him if he is standing in a specific spot though, so it’s a bit inconsistent to do, but you can use the cameras to see where he is. The only downside is that the boss usually kills your allies while he is moving into position, so usually only one person survives. You also get a different ending depending on who you side with, or some unique dialogue if you kill the inhabitants without turning on the power.