Metal Gear Rising: Revengeance walkthrough: VR Mission 013
VR Mission 013 is fairly easy to find. It's located at the beginning of File R-04. Once you have control of Raiden in the lobby, check the upper left corner of the lobby, past the stairs, to find a series of glass cases. The computer console is in one of these cases.
Mission 013 is another elimination round. You need to wade through an increasingly-difficult number of foes to achieve your objective. You know the drill by now.
There are only two waves to this battle. That said, it's still quite difficult to get a gold ranking thanks primarily to the nature of those waves. You'll be cursing the first wave in particular until you figure out how to kill it easily…
… as it consists of no less than seven unmanned Sliders. The unmanned ones are much more annoying than the manned, as they move a lot faster, dive bomb you from all angles, and like to stay just a bit out of your range while attacking. They don't take many hits, but landing said hits is a problem.
The secret to easily killing these things is your sai. Equip it and use it to drag Raiden over to the nearest Slider. He can then Zandatsu it, steal its energy, and use that to take on the next. Rinse and repeat. The Sliders like to form up around Raiden, so you may be able to kill two each time you do this. Move quickly, though - the Sliders won't be caught off guard for long, and if you wait an extra second or two, they'll move out of Blade Mode's range. Keep doing this until you demolish the lot of them.
The second wave is a bit easier, though it's by no means easy. The number of Sliders has been reduced to four… and they have two Hammerhead escorts helping them out as well. Yay.
The Sliders are still an utter pain, so take them on first. Use the same method as before. The Hammerheads will fire on you while you're doing this, but most of their hits won't hurt terribly much, and you won't be atop the Sliders for long anyway. You can give up on this when their numbers have been reduced to one, as that single Slider will likely get destroyed by what's to come anyway.
Now for the Hammerheads. The area is littered with Homing Missiles, and you need to use these missiles to take out the choppers. Equip them and fire. You don't need to aim, however, thanks to the tracking capabilities of these missiles - just click the fire button when you're pointed at a Hammerhead. Once the Hammerhead is down and stunned, either move in close and slash or fire another missile. Quickly enough you'll whittle them down to Zandatsu health and win the fight. Getting 3:30 for the gold ranking isn't that difficult, so long as you get the Sliders out of the way first.