About two weeks ago, while running Tomb of the Shadow King (a level 8 quest) on Elite, my level 13 Rogue was instantly killed by something. At the moment this happened, my Rogue was at or near full hit points (about 170), burdened, and wearing a Mabar Cloak of Night, Minimum Level 12, with Deathblock.
I can provide more information. A friend and I, each with a Cleric hirling, were making our way through the tomb. A third character with a Cleric hirling remained at the tomb entrance and was not involved in the fight (6 party members, total). We engaged a mixed group of monsters including about 6 Umbral Gargoyles and at least one Wraith. My Rogue was dancing in and out of the pack, trying to maintain the attention of the enemies, when hit by a Ray of Enfeeblement or something else that drains Strength. She immediately became Burdened but, to my knowledge, not helpless. I successfully backed her out of the pack, began to order a Heal from her hirling Cleric, and then she was struck instantly dead.
After a pause of shock, I quickly went to the Combat Log to see what happened. The log showed all her buffs removed (Blur, Super Heroism, Protection from Evil, Protection from Elements), then a death statement, but no line for what caused the death. To my knowledge, she did not sustain massive damage before her death.
My first thought was that I accidentally equipped her Cloak of the World Shaper and she was then struck by an instant kill spell, but her Mabar Cloak of Night was equipped. My second thought was that Ray of Enfeeblement left her helpless and this turned off Deathblock, but there was no indication of a Helpless state before her death.
Can any of you offer an explanation of what happened and, perhaps, a counter? Perhaps I misread the Combat Log? Perhaps she was Helpless and Deathblock ceased functioning? Perhaps she was hit by some massive damage attack while helpless? This continues to bother me so I decided to come here and ask for advice. Alas, I did not save the Combat Log as I have no idea how. For what it is worth, all my characters now carry large stacks of Lesser Restoration potions.