There are a few windows up top that you can use to kill enemies through, just don't walk by them even if it is dark. You will see a few enemies atop a dance floor in the top part of the level, you can shoot them from a distance to kill them without causing too much havoc. Bait enemies around corners and kill them when they come at you. If you find things way too dark to see, wait a second for the lights to pulse back on and continue moving. Look out into the distance often to see the movements of enemies and proceed when it is safe. You can use the katanna you have equiped from the start to take out a few of the enemies when you first enter and afterward grab a gun to kill enemies from a distance. To get through this mission you need to exercise more caution than ever before. The lighting of the level makes things very hard to see especially when some enemies are stationary in areas that are incredibly dark on screen. The mission has you taking control of the mob boss from earlier in the game and attacking enemies in a nightclub.