my first run through I wasn’t counting but I assumed that I had triggered enough death rattles – my n’zoth mercenary task 5 however did complete at that point. I thought maybe because it showed up the other one just didn’t because of a visual bug but I confirmed it didn’t complete.
I ran through again and this time made sure that there were 10 triggers and I got no credit.
Same here, did it a couple of times with more than 10 deathrattles getting triggered in the boss fight. (and yes, in heroic)
Same here 
And i see event ends in <1h in the last 2 hours.
fortunately the “ending in” deal is a known bug and the event will run until the next patch.
I checked old guardian’s video again and apparently there are countless people with this same task issue. some say it completed for them after multiple tries – not sure whether I’d rather wait or keep trying.
I have tried the workaround to just use the fighting nodes and tried it 5 times over, it does not trigger at all.
Update: After about 15 tries i finally got it, dont know how since i did the same thing over and over again.
So i cant tell what the difference was…
yeah I was afraid of that so I stopped attempting it for now. sorry about that =\
Same issue for me. Have attempted multiple times using every workaround I can find. Nothing works.
the same by me severel runs in every constallation no quest completion. great job blizzard…
Finally got this to complete after 10+ attempts. I lost Balinda on the climb, but was able to rez her at a healer. The only way I got it to work (I think), was to not have any deaths at the boss. IDK if that will help anyone, but I don’t know what else happened differently.
I had boss fights with or without a merc’s death – nothing worked.
Yeah, I was just taking a shot in the dark. I truly don’t know what the issue is. Seems totally random.
Same issue; will retry a few times since the youtube thread seems to indicate some RNG determining whether this task registers as complete or not.
Just completed it. You have to get 10 in a single round. 4x on boss and 2x on each flayer then it completes. Need chiji, Belinda, geddon
Same for me,
I saw Old Guardian video, i did exactly the same several times with at least 12 deathrattles triggered an never got the task done…
Not gonna try anymore
After doing this task 10 times this turned out to be te solution.
This is not a consistent workaround. Many people have gotten the task completed despite not doing this and some people have not gotten it completed despite trying this.
As of now no one knows what the conditions are for getting the task done or if the conditions are even under the player’s control. It’s probably not worth trying until they fix the bug, and if someone does want to try then the best way is to do it via the fastest method to maximize the number of bounty completions. Each completion has a practically random chance of giving credit for the task.
Same issue for me. I made sure that I waited for Dragonbone to summon the three adds, four times to make sure that I had more than ten deathrattles go off. No credit for the quest. Did the run a second time to be sure–same result no credit. Besides the twelve deathrattles there were at least five others going off during the fight. It should be more than enough.
Same issue as everyone else. More than 10 deathrattles triggered and no credit for the task despite multiple attempts.
thankfully a fix is in the works.
From what I have read elsewhere it seems that the criterion is actually ‘10 deathrattles in one turn’. This worked for me after many previous attempts.