Drumuru in the latest wing of LFR is an interesting boss. On LFR particularly, his mechanic seems very harsh.
First off, funny story in our LFR. We wiped on Drumuru something like six to eight times. On the kill attempt, we were down to 2% with only the tank and a couple dps alive. One of the dps, who we'll call Dave, had been a bit of jackass on earlier attempts. At the 2% mark, Dave wrote "This carry has been brought to you by Dave". Then he promptly died, to the jeers of the rest of the raid. Luckily the tank and the other dps finished off the boss.
The problem with Drumuru is one of his abilities. He covers the platform in some purple fog, but there is a path in the purple. You have to get on the path and follow it. This ability seems incredibly hard for people to deal with. On every attempt we lost more than half the raid.
We've seen mass death effects like this before in LFR. Think of the ice walls in Hargara. The thing about the ice walls, however, is that everyone died to it on the first attempt, but on the second attempt they were able to understand the mechanic and work towards mastery. An early LFR Hargara would go like: first attempt, 15 people died. Second attempt, maybe 8 people died. Third attempt, 4 people died and there was a kill.
On LFR Drumuru, there is no improvement, no indication that people are mastering the mechanic. They're just dying.
I think that the major reason this is so is due to the graphics chosen. The fog is a mixture of writhing purple lines and emptiness. I found it difficult to tell where the path was, even when I was on it. Not to mention that the room is already darker than normal.
I was able to survive this mechanic about half the time, but I felt it was a bit random whether I did or not. Even though I knew where to go, and what to look for. Heck, one time I ran to where I was sure the path was, and instead fell off the edge of the platform. At least I was right that there was no fog there.
If the fog had been more solid, more filled-in, I think people would grasp the mechanic sooner. Or perhaps if it was a color with a stronger contrast.
All in all, though the rest of the fight is good, this one mechanic is too punishing for LFR. It's an insta-kill that too many people are finding too hard to understand and master. In my opinion, this is entirely due to the choice of graphics used.