During the first phase, use Empower to get through his shield, then use the 
Panzer Rocket Launcher and Veil Blue Rocket Launcher. During the second phase, 
use the Slow Motion or Empower to defeat him. During the third phase, instead of 
running up the ramp, shoot him with a sniper rifle or rocket launcher. Move 
slowly, and get to the stairs. Have a weapon ready to kill the four waves of 
Sniffers. Then, shoot him until he falls. During the fourth phase, just shoot 
him and use the explosives.