I'm just going to go ahead and say it. The fight is stupid in it's design. There is no leeway to avoiding plumes/landslide and unless your ping is low, players are going to have a bad time eventually. I have relatively good latency experiences with the fight and rarely get hit but its perplexing to see that sometimes on my screen, I'm still in the plume and the cast bar has gone off but the server registers it as avoided.

Punish the complacent player for standing in bad. Don't punish the player who makes a effort but doesn't have twitch like reflexes in a non-twitch game. I'm curious to see the metrics on SE's side of how many runs are successfully completed versus failures.