Yep. I believe I mentioned a while back that the tanks in Nark's run had Shadow prot gear and Fire resist gear for this place...and Mirk I believe was the one that had forgotten to switch out after the fight and was taking some massive fire damage from the respawned core/ancient hounds as we left the cave from fighting Luci and Magmadar. What can we do to help our tanks get Shadow resist gear? I'm not real familiar with tank pieces at all.
That's why I carry three shields on Huato now...the Zulian Defender for most places, Rattlecage Buckler for the shadow resist in Scholo, against Luci, against Gehennas, etc, and the Draconian deflector for the fire resist for Magmadar, Geddon, et all. Even with the priest's shadow protection buff, my shadow resist was around 80-something. I was still taking 1000, 1500, or 2000 everytime one of those Impending Dooms popped - it seems that unless you are above 100 on Shadow resist it is random how much damage you take when it goes off.
The Tier 1 epic sets that come from Molten Core all have fire resist and shadow resist spread out amongst the pieces of the set. The more time we spend in there and get the gang geared up these encounters will get easier because we will be taking less fire, shadow, and even physical damage.