There's an exploit i found that will allow you to basically get 2 of these mobs to spawn whenever you want. there is a catch, there's always a catch. first you need to have the quest Troubled Spirits of Kel'Theril.
The quest information, where to get it, etc. is here
Now, DON'T COMPLETE THE QUEST. follow my instructions. when you are at the Highborne Relic Fragment, mine it like normal but don't take the item that pops up!! instead, close the item window and wait. sure enough there will be 2 suffering highbornes that pop next to the fragment thing. you can do this over & over, just make sure you don't pick up the item.
