Tip: During this battle many Zombies will join in, simply ignore them as there is more than enough room to get around them.
Like in the previous two battles against the Nemesis, you’ll want to do a quick loop around the arena to stock up on Ammo and Healing Items, then you’ll want to continue running around whilst using the Grenade Launcher to stun the boss.
After you’ve taken off a certain amount HP he’ll begin to run around the outside of the arena, here you’ll want to wait for Carlos to give you a number and then you’ll need to shoot the two red lights on that generator to electrocute the boss. Once he has fallen down to the ground, you’ll want to focus fire at his heart to deal maximum amount of damage. Finally, as the Nemesis comes close to death once again he’ll try to hit you with his tentacle, this can reach you from a distance, so you’ll want keep to the edge of the arena to avoid it.