The Oculus' achievement, however, is one that needs an even closer look. And 4 Haelz kindly provides exactly that, with an in-depth guide to toppling two achievements in one, both the Emerald and Ruby Void, by doing the boss with five Amber drakes. The Amber drakes are usually meant as DPS, which makes this fight extra tough: you can't take much damage at all, because you can't get any damage back without healers. So what it requires, instead, is communication and coordination. Basically, you use the drakes' Time Stop ability to slow the fight down, and then try to do some coordinated kiting while DPSing like mad, all the time hoping that you can bring him down before he takes one of you out.
As Bell says, once you get the idea (and have wiped a few times -- you should probably be riding the drakes naked, since not only does your gear not affect their performance, but it'll save you repair costs), the fight's not actually that hard to pull off, but it's the learning that's going to hurt.