I've definitely had a single pillar disappear multiple times on my first run, even though we were never grouped up on the same. We actually gave up on the encounter and only figured how to choose a pillar the next day.

Last night we accidentally hide between two pillars on hard mode one run and it only took away one pillar.

Right. On normal, it would have taken out two. We definitely had that happen when we were first figuring out the encounter.

That doesn't make sense... Why would normal be more punishing than hard?

We've also had runs where we stood behind multiple pillars and only 1 dissolved. I'm starting to wonder if it's linked to the amount of health the boss has left. Like if you do enough damage in a single arrack round, 2 pillars dissolve instead of 1?

There is no bottom left pillar, so you all should have died.

There's top left, bottom middle, and mid right. So what are you guys doing?

The pillar on the left extends down, below the platform. So you can group up on the left side below the platform and hide in the shadow of the lower portion of the pillar.

If someone is standing behind a pillar when the oculus fires, that pillar will be destroyed. My team has done this many times.

Hmmm... My group has found the opposite to be true. We've had guardians behind multiple pillars, yet only a single pillar dissolves. I wonder if it's linked to the amount of damage done to the boss? Maybe if you do enough damage, 2 pillars dissolve instead of 1?

When we were working out the mechanics, we were doing WAY too little damage to the Warpriest to kill him in 4 rounds - and we had attempts where all 3 pillars would be taken down in a round because we didn't know to group up. I just assumed (until this thread) that everyone else had identical experiences, and we all learned to group up on a single pillar to maximize our time to kill.

I'm as confused as you are, now. :)