I've been looking around this place for about an hour and can't find the group challenge. Asked in zone chat and nobody knows either. The achievement states, "Defeat Zatalguch in its subterranean lair." Anyone know where that is inside the dungeon?
It's near the end of the dungeon, you'll find a daedric gate leading to a snake-thing boss guarded by a few clannfear. Turn to your right, there is a tunnel leading to the boss you seek.
I solo'd as well at lvl 48. I am a healing Templar. All I did was stand max range and strafe back and forth blocking bolts. The blame breath doesn't even reach you. Took a little while, but he went down pretty easy.
Also to note. First attempt on him.. I got him down to about 10% health and a group came in and killed him. I did NOT get the credit... I had to wait for respawn and fight him again to get credit.
This is literally the worst dungeon in the whole of ESO, cant understand how this got greenlighted, Still have problems with this one, bosses buging, not spawning, general confusion over the insane layout, always try to get this done as soon as i can, have a small hope that they scrap it all together someday.