The Oculus

If you're looking to solo this instance, the troublesome one is Eregos. I have created a video guide to solo'ing him using an Emerald Drake.

http://www.youtube.com/watch?v=RLYAm6prTps&context=C3baffa3ADOEgsToPDskIgzC3bFJTNvngxPWtMvLlB

If you don't want to watch a video, here is the general idea of it:

Having enemy health bars visible will be essential to this strategy

1 - Start the fighting by Stacking 3 (#1 Leeching Poison) on Eregos and then hit him with (#2 Touch the Nightmare).
2 - Keep spamming #1 until he spawns the first drakes
3 - For me, each drake took 2 stacks of #1 to kill them. Also, one (#2 Touch the Nightmare) will instantly kill a drake, you must have poisons on constantly to heal through the self-inflicted damage. So, target a full health bar, hit #2, there are 3 more whelps, rotate through them using #1 ONE time on each of them
4 - Switch quickly back to Eregos and #1, if the original poisons are still ticking, you will only need to hit #1 a single time and it will refresh all 3 stacks of poison.
5 - Finally, switch quickly back to the other 3 whelps and refresh the poison by hitting them each with #1 a single time. This will finish the whelps

Basically, by hitting each drake with #1 twice, and insta-killing a drake with #2 whenever it is refreshed, you can keep ALL of the drakes killed. It takes some practice rotating between targets, but just keep your priority killing the drakes, if the poison wears off Eregos it's okay, you can quickly stack 3 when you have two poisons on every drake. If you get efficient enough at killing drakes, you can blow an extra #2 on Eregos for added damage.
By keeping the 3 poisons on Eregos and an extra #2 every once in a while, his HP will consistently drop. It isn't fast at first, but once you get the rotation down, it was much faster.

Happy Solo'ing friends!

At lvl 110, this is very straightforward to solo:

1. Make sure your character has any ranged attack. For example, Poisoned Knife for Rogues.
2. Get any drake and ride up to Eregos.
3. Flail away for a few seconds until your drake is dead.
4. Once you are dismounted and falling (sometimes you get a parachute) spam your ranged attack. Eregos will go down with one shot, maybe two.