It's always the floor mechanic. It wipes the group every single time. Fans get people the first time, but usually after that, people know how to avoid it. As soon as the floor starts changing colors, though, you may as well go ahead and get ready for a second attempt. The group I was in last night wiped FOUR times.
I was on DRG and me and the MT kept trying to explain to everyone how the mechanic works. I move constantly during that phase, going back and forth. I don't even wait for the stacks. So, finally, I just told everyone to follow me.
To the person above that said this is the trial they were going to be doing next, think of it like ping pong. That's what I told the group. Just keep going back and forth between the two halves. We downed her after I explained it that way.
Then I hung myself. But I'm okay now.