Well, i searched and i want to have deleted this, if it is a repost.
Today i was in Hall of Reflections, and after the first boss, the event starts where the lich king follows you, and you have to escape.
there is an achievement for doing this in 6 minutes, but random its very hard....
NORMALLY
When you get out of this hall you can run up on the right... normal way, but if you run to the edge of the left side and let the king pass, you wont be damaged by lich kings aura, he will just run towards, and mobs will come to you, which means you can hold up more space and so gain more time to kill the mobs. normally you would think: whats up with these stones in the end? ... well, you can just pass it through, seems to be a bug or something like that, i dont know.. Hope this was a little help 4 you!