Perform the following steps to easily defeat the final boss:
Part 1 Use Empower to get through his shield. Then use the Panzer Rocket Launcher and the Veil Blue Rocket Launcher.
Part 2 Use Slow Motion or Empower.
Part3 Instead of running up the ramp, snipe him with a sniper rifle orrocket launcher. When you are about to climb the stairs, have a weaponequipped to kill the 4 legged sniffers. Then shoot him until he falls.
Part 4 He will now have no power ups. Continue to shoot him and use explosives to kill him.