pick up the little guy who falls in front
of you. Carry him right and toss him through the other block then go back,
climb up the ladder, and roll down the slope. When you go through the small
gap you just opened, jump once to get over to the next platform, then jump
again for the Diamond. Jump a third time to get over to the platform on the
right side and jump up to get the Keyzer.
depends how you prefer to play. If you prefer sniping, the 50cal sniper is a good option. Remember, silencing any weapon makes you invisible on radar when you shoot. If you like automatic weapons, the m16 has great accuracy. Add a heartbeat sensor, and you can a radar simulation on your gun.
You have to level up several more times in order to put a better fight. The req. for that mission is 30. meaning you should be 32 + to beat him comfortably. Rocket launchers and caustic snipers have done the job.