You have to do the kolkar quests first. You can find them at the oasis. If i remember correctly there are 2 2 start with. After completing it will become available if that was your question since im not able to see whats so hard about that quest you linked.
When I did it I had to do a few other crossroads quests to get access to it. There are a bunch of them that send you to the other oasis areas, after I did a few concerning the southeast one it let me do the rest you need for the wand.