Correct, just verified it last night its not a curse. Fixing.
There is no curse. Poison Blast is a massive, uncureable Noxious AE with about a 20m range. If your healers rock, your tank can take it. If not, time your tank switches appropriately. Recast is 60s, Swipe does not affect it.
Death removes the Flames immunity timer, so upon being rezzed, you can immediately get the Flames buff and DPS the mob again.
Adds work like this:
Occasionally, even if you have the Flames buff, someone in your raid will spawn a single add. If someone is DPSing without the Flames buff, they will pop THREE linked adds.
In any event, these adds will, as mentioned, go after the player in the very first slot in the raid. Make it a plate tank. (We run 3 plate tanks for this encounter)
Have this tank, plus 2 healers who will stick with him, start near one of the Ysidriax Mounds. There are four of them in the room. The adds will usually run directly to that tank in slot 1. When the tank sees an add approaching, you can right click and choose "Disturb this mound". Double click works as well.
This will spawn "a ravaneous ysidriax" (looks like a centipede) at the mound who is capable of eating four adds. Once he has eaten his four adds, he will disappear and your add crew will need to move around the edge of the room to the next mound, spawning the centipedes as necessary.
The flames effect that comes from the fire lasts for 60 seconds, and is followed by a 25 second immunity. If you die with the flames effect on you, it is removed. Keep this in mind! If you die, *don't* DPS the mob until you are able to get the Flames again!