So I was doing mogs on my warlock with voidwalker. In Throne of Thunder under the golem boss I was ok and VW was not taking damage, but all of a sudden the VW dies. I tried again and it looks like after a certain amount of mobs are on your VW or yourself you start taking heavy damage. Same on Paladin. All of a sudden I go from absorb and miss to taking heavy damage and die in about 2 seconds.
Is the magic damage on old raids tuned too high?
Is there an amount of mobs you are allowed to fight against a flat number that once the number is exceeded that you start taking heavy damage?
Not sure why I am dying in raids from cata (bastion of twilight has same issue).