Mars is a red desert wasteland and serves as the home of the main Cabal force. Most of the structures and fortification in the area are from the Cabal, though the Vex can also appear. You’ll find Relic Iron in this area and rarely Fallen.
Once again you are on a new planet and must synchronize your Sparrow with your Ghost’s help. Head to the bunker on the right and deploy your Ghost. This brings some Cabal, a new enemy type. The Phalanx have a shield that blocks all damage so shoot them in the hand so they open up for a headshot. The Centurion has a Solar Shield and fires explosives so be on your toes.
After defeating the enemies, hop on your Sparrow and ride through the Scablands where the Vex and Cabal are fighting to reach Giant’s Pass. There are plenty of Phalanxes and Legionaries in this area; just go to the left to find the computer you need to scan. Once you do though, a dropship comes by with some tough foes. One of them is Bracus Thoourg , a Major Centurion that has the access key. He brings Psions with him, little creatures that are similar to Dregs. Take cover and avoid their blasts before focusing on Bracus.
Valley of the Kings
With the access key in hand all you have to do is plow through the next Cabal outpost in the Valley of the Kings. Stay away from the left side as there are some powerful Vex that way. Scan the device inside the building then return to the Tower to get a Sparrow Upgrade .