Metal Gear Rising: Revengeance walkthrough, Part Four: Hammerhead
Raiden has managed to demolish Blade Wolf, one of Desperado Enterprises' robotic AIs, in single combat. That new gear is looking pretty good. Blade Wolf's only the beginning of the fight, though, so Raiden had best buckle down and get ready for even tougher challenges.
After partaking of the Sub Weapon tutorial that opens up post-Blade Wolf (which is pretty self-explanatory, and not all that useful) you'll find the path ahead seemingly clear - though if you turn on AR you'll notice a number of soldiers ahead. There are three, and two have shields. Draw them forward and wait for someone to attack so you can parry. This will demolish the shields and turn them into normal soldiers. Tear them apart.
Check the right side of the street ahead for Repair Nanopaste in a box and carry on to the bridge ahead. Two helicopters will begin to attack you with missiles. Use Ninja Run to dash across the bridge (don't worry about dodging obstacles, they won't impede you at all), pound the buttons when prompted, and prepare for a bit of a fight on the other side.
The Hammerhead that takes you on is a lot easier than it looks. Check around and you'll find Homing Missiles between the arches and propped against walls in this small area. Use these to target the Hammerhead from below whenever it stops firing at you. Once you damage it enough the Hammerhead will move from one side of the area to the other, launching constant missiles. Follow the prompts on the screen to get overtop of the Gear and use Blade Mode to rip it apart. Make sure you use Blade Mode as soon as you get overtop or you'll overshoot the Hammerhead and have to start over.
Go through the next arch. Check to the left to find an EM Grenade in a box, then pause behind the APC on the side of the road and have a look ahead. There are numerous soldiers, including two curious flying creatures (they're just soldiers with flight harnesses). If you're sneaky you can get onto the buildings to the right side of the street (you'll find a Repair Nanopaste at the top, to boot) and ambush at least one of the flying soldiers before having to kill the rest. If you want to go the direct route, either shoot down the fliers or use the APC or buildings to reach their height, and Blade Mode to rip them apart before you land.
Before you go any further, check the street. There's a Repair Nanopaste in a box on the right side, and if you scan the left you'll find a way up onto the buildings. The first building on the left (from where you fought the Hammerhead) is home to an Electrolyte Pack and, even better, the computer for VR Mission 002.
You'll find the enemy compound at the end of the street, but there's a problem: the gate is ID locked. You'll need an enemy hand to open it up. Time to double back and find a platoon commander of a decidedly cyborgish disposition.
Go back down the street. An APC will pull up, and several soldiers will get out. Your task now is to use Blade Mode to literally disarm these soldiers so Raiden can steal the proper ID. The first three are useless, but when you reach the end of the street you'll find a fourth soldier who has the proper hand. Slice it off and grab it before Blade Mode ends. This will allow you to enter the compound without a fuss.
Did you kill them all? You can still get through… though you'll have to slice up the door and fight a combination of ground and flying troops to advance. This route isn't quite as quick or reliable, but it's at least good combat practice, right? Right. Either way, once you're in you'll have to face another squad of soldiers. These guys all have swords, and one is a bit more advanced than the rest, but they're still standard fare. Parry your way to success and head into the compound.