STORY MISSION 16: Eye Of A Gate Lord
Recommended Lv: 13
Objective: Scan the vex network
Time for another trip across the over world (Super Mario Bros. over world theme plays, I wish). This mission focuses solely on the vex, so be prepared to kill a lot of them over the course of this mission. A large contingent of vex will be strung out along the approach to the conflux (glowing white enegy pole). These forces include plenty of goblins, several harpies, a few hobgoblins and near the conflux itself are yellow health minotaurs.
Take your time, work through the enemies and aim for the core or eye to take them out efficiently. The only real danger is being too hasty and triggering the yellow health minotaurs (thanks to the short distance teleport they sometimes employ) and getting swarmed. When the area is at peace once more, interact with the conflux for a new objective.
Objective: Find the endless steps
As you follow the new marker, you will enter a darkness zone. A group of vex (goblins) will be waiting to say hello when you enter the campus 9 area. After dealing with that group you'll stumble across the real threat of the level. Spawn gates. These stargate looking circles of metal generate vex forces every few seconds and don't stop until destroyed.
So your primary focus should be on destroying them asap. Due to the "creation" of enemies it is impossible to detail exactly what you will face as you follow the marker, destroying gates as you go. In my experience, you will run into goblins, several sniper hobgoblins, minotaurs, harpies and at the end your first hydra.
New enemy: Hydra (vex)
Weak spot: Core/ eye
Hydras are large metallic insect looking creatures with a rotating shield that protects them. This shield is immune to all damage but will continually rotate around the hydra, leaving it vulnerable about half the time. Shots to the glowing core/ eye work quite well in bringing it down fast. They often also have a highly damaging melee attack if they are classified as a "boss" so avoid getting too close in general. Melee attacks do minimal damage and are often intercepted by the shield so don't bother.
Their purple plasma blasts are quite damaging and rapid, so keeping in cover is quite a good idea. One of the best ways to take these enemies down is from long range with a sniper rifle (out of range of their plasma blasts). Maneuvering between cover and firing when you can also works but is more dangerous. And no, they have nothing to do with G.I Joe (although it would be interesting if they sounded like Cobra).
After destroying the hydra and the final small gate, a new objective will appear.
Objective: Ascend the steps
Head for the nearby marked area to find (oh happy happy joy joy) a giant gate. Nothing bad will come out of this I'm sure. The goal here is to approach the base of the large gate and activate it to summon the gate lord. That means destroying all the vex forces between you and the gate (believe me, you don't want any extra enemies around when you summon the gate lord). Deal with the goblins, harpies, hobgoblins and minotaurs in your path until you reach the spot.
Objective: Summon the gate lord
As you get close to the gate, a glowing circle will appear on the ground in front of it. Step inside and the gate lord will be on its way.
Objective: Slay the gate lord
Despite being called a "gate lord" it really is just a large minotaur. Unfortunately, he also summons swarms of vex minions, moves fast and deals hefty damage. So backing away and taking potshots when you can is the best method for dealing with this guy.
Don't be afraid to fall back, remember that this is a darkness zone. You don't want to start this fight all over again. Play defensively, use your abilities to quickly destroy the swarming minions and then return to firing on the gate lord. After enough shots the gate lord will finally drop and the mission will be over.