I very much tried to explain why this mechanic sucks in this post here: Server Patch 5/25/21- Hardmode Raid Adjustments - #6 by blueduckyy
Here is a video showing why this sucks: https://www.youtube.com/watch?v=oUziERGDNLE
(1) The chains start and since it is below half health drop pools.
(2) Within a second, the boss jumps to a chained person which then drops a pool on both chained people again.
This to me is the instant death mechanic. Rather than try to group up and absorb the jump, accept that person will die. Because if you try, it’s more than likely others will be die due to the pools being dropped.
In my opinion, the DPS check of this boss should be trying to do pool management enough that you kill it before enough pools are down that you have nowhere to run. To at least give people hope that they’re not going to be instantly murdered.
Edit: They are not random poison pools! 2 people get randomly chained and they will get pools twice, once when chained and once when a jump happens. The pools are not random, the chains are random.
Edit: Sorry for the bad quality on the video.