In Endless Archive, 4th iteration (i.e. when you've got 3/5 towards the achievement), there's a big crystal behind Aramil. Shortly through the fight, it activates, and kills me in basically 2 seconds before I can react.
There's precious little showing up when I google it, just Alcast saying that you need to destroy it with a DPS check without explaining why or how.
2 seconds seems way too little time to react. There does seem to be a big AoE plopped down beneath me, but I was stunned at the same time, and before I could break free and roll out, boom dead. This has happened to me twice now.
What's going on here, what am I missing?