Атаки против них при 1 хп должны эвэйдиться, если только игрок {не имеет нужного квеста и не трогает кристалл}.
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От 79023 (215 – 2) 16.08.2007 (Обновление 2.1.3) I have discover a glitch. when some of these guys get at 1 hp for some unknown reason they look like they fade . after about a minute they become invinsible. i don't know how / why when / or if it is just my sever or luck. but this has happened several times. if u notice they arnt dieing after 1 hp run u r experiencing my glitch
This is not a glitch. The servants that can be found in the Blasted Lands are the objective of the quest "The Stones That Bind Us" (http://www.wowhead.com/?quest=2681). The way to kill them is to get them down to about 5% health (when they 'fade' as you call it) and then destroy the crystal that they are standing next to (right-click it).