Part 28

Vamp Boss Fight: Vamp is agile and throws knives, also using a powerful melee combo. He doesn't dodge gunshots as much as before. When he charges, unload your clip to deal significant damage. After his initial defeat, he revives. Recall that Naomi explained Vamp's immortality is due to his nanomachines. Use the syringes Naomi gave you to suppress these nanomachines. Equip the syringes and fight Vamp again. The goal is to get close enough to perform a CQC chokehold. This can be done by attacking him until he gets up or charging him after he knocks Snake down. Once in a chokehold, use the syringes on him. His life gauge will drop to zero, ending this phase. Using the syringe is considered a non-lethal takedown.

Suicide Gekkos: Raiden appears to finish Vamp. Snake must protect against kamikaze Gekkos. Use Crying Wolf's rail gun (hold R1 in aiming mode until the charge meter is full) to destroy Gekkos in one shot. Stay under Rex for cover, but move when Otacon warns of attacks from above. Destroy approximately twenty Gekkos. Rex provides good cover from Gekko attacks.

Escape from the Underground Base: Snake must escape an exploding underground base while piloting Metal Gear Rex. Rex has three main attacks: Gatling gun, AT missiles, and the FE Laser. You can also charge by pressing X and perform a kicking combo by pressing R1 when not aiming. Gekkos are vulnerable but explode upon destruction. To avoid damage from explosions, either destroy Gekkos from a distance with the machine gun and wait for them to explode, or rapidly charge through them before they detonate. You have about five minutes to reach the exit. You can also choose to farm Drebin Points by killing endless Gekkos.

Metal Gear Ray Boss Fight: You will face Metal Gear Ray while piloting Metal Gear Rex. Rex's available attacks include the Gatling gun, melee attacks, FE Laser, and AT Missiles (cycle with R2). The kicking combo (R1 when not aiming) followed by a Triangle button special attack when close to Ray is effective. Use missiles to stop Ray's charges and the Gatling gun to destroy its missiles. Avoid the FE Laser due to its long charge time. Ray's attacks include a water cannon and missile barrage, which it uses when given space. If you maintain pressure, Ray will resort to charging and tackling. The key to winning is to stay as close to Ray as possible.