Servants of Allistarj are level 54 - 55 followers of Archmage Allistarj. They can be found in Blasted Lands. The cannot be killed by normal means, to kill them you'll have to damage them down to about 5% of their hp, and then click the crystal near them (this can only be done if you have accetped the quest - File:Neutral 15.png [57] The Stones That Bind Us).