Once inside you will encounter MANY groups of Group X2 Lizardmen. You will also find a couple of NPC Soulstealers. What you need to do is clear all the lizardmen around these NPCs. After a minute or so you will see message about them conjuring up the remains of an old foe. It's a level 38 ^^^ Group X3 Skeleton. The NPCs also become killable and are Group X3 as well.
Once you have killed all the NPCs and the 2 large skeletons, You can head to the island where the old gate to Fear is located. You will now see another NPC and you'll have to kill all the Protectors of Fear around him. Once you kill all the mobs, He will then begin casting and you'll get a message about the waters rising. At this point Alizasaur and 2 Protectors of Fear will come out of the water, kill the NPC and then you can fight them. Unfortunately for us, everything was gray to me at 50, but Alizasaur was a level 40 ^^^ Group X3 mob. His AE did about 1500-2000 but once he's out of power, he's cake. We got no drops since everything was gray, but I would HIGHLY suggest 2 solid complete groups of 46s to attempt this zone.