I soloed most of this as a rogue up to General Drakkisath . If you are interested in obtaining the key for ubrs then you need to do a series of quests starting with ( seal of ascension) from vaelan in lbrs. http://thottbot.com/?q=1344 I also soloed most of this and killed bosses. It will send you to kill (Emberstrife) the dragon where you have to mind control him. Then simply return to vaelan.