I see this in 4-man dungeons sometimes. Someone puts an insane amount of damage shield on everyone so that no one could die even if they wanted to. What is this skill or set or whatever does it?
I hadn't even thought of magma armor, that could have been it too. Bone shield probably not though, ally has to activate a synergy and it's only 60% health. Even with a 20k health DD that's just 12k compared to the 21 or 30k magma and barrier would be respectively.