Sorry SE, but endgame won't work if you don't fix something.

[Cienna]

you can indeed avoid the mechanic based on the enemy cast bar.

http://www.youtube.com/watch?v=QsHuXAl-bOY

At 6:21 landslide cast begins
At 6:22 player leaves aoe with cast bar at 75%
At 6:24 player is hit by landslide and knocked off

They were out of the red area well before the cast bar finished. They still get hit. There are many more examples in this thread, like Sunarie's 2nd video about 10 pages back, and heaps more in the 100+ pages of this thread. It is broken.

So not attacking you, but you say we can avoid getting hit if we pay attention to the cast bar, if moving out at 75% doesn't save us, what does? I think that moving out at 75% should be safe, but yet we still get hit.