Roughly half an hour here. Solo as well
Here's how I did it
The first load of encounters can be easily evaded. When you first meet the covenant just high tail it past them all to the right and you can miss every fight through that section of the valley, just be sure to stick as far right at possible, (without falling off the ridge haha).
When you get to the driving section carry on as normal and follow the road all the way to the right. Eventually you'll get to the encounter where there are a few marines fighting the grunts by the river. Drive up, drop of Jorge and Carter *important* use a frag to knock the destroyed warthog out of the way, and when the dropship leaves (avoid those concussion rounds!) just go on an all out splatter spree with your jeep! haha. Wait a ways away while the other dropships come and drop more troops off, rinse repeat.
After getting picked up by the Falcon, as it drop you off, jump out of the left of the dropship (look to your left as opposed to the right, where the action is happening), run up the stairs, grab a DMR (and maybe even the Armor Lock while you're there) and pick off the initial enemys there. When the next load of dropships come, high tail it indoors where Kat is and cower in a corner (srsly) until Kat's done with the door.
Next section, straight away, grab a new DMR and *IMPORTANT* do not leave the doorway you started at.
The Zealot firing at you with that concussion wants you to have a bad day, so evade for the time being and stay where you're at. Moving up on him will cause him to run away, and the focus here is to keep him where he is at and kill him there.
Poke out with the DMR and nail the grunts and jackals, but let some get close. Hopefully after they are all close enough one will have dropped a plasma pistol close to you. Grab that sucka and go all noob combo on that Zealots behind.
Reason for killing that Zealot here is, there should one be one, yes ONE Zealot at the end. Unfortunatly, it's the one with the energy sword >_<
Plow through the grunts and get to the final room. Make short work of the grunts here from AFAR, then when the elite is the only thing left, run under the arch to entice him over.
The thing you want to aim for here is to get him to chase you all the way back up to Jorge, but he's horribly fast, so be careful. Retreat up the stairs where you came from in the corridor and if all went right, Jorge and the elite should start throwing down. While they are duking it out close quarters, sneak up behind the elite *carefully* and assassinate that sucka!
Skip on over to the button and activate that relay. Congrats, you just got mad cR!
Hope that helps anyone, and if I'm a bit vague in any sections let me know, and I'll try my best to clarify
- X.
