Serpent death immunity depends on persistent counters
What
The node has been changed and being worked on continuesly.
After hitting 12% on a defender, LC used to get indestructible eating a sp3, titania ignored it too.
They have made the node to bypass these extra time consuming actions, including sitting out sp3 animation in the past, and knocks the attacker down instantly.
I think what OP is saying is that Serp’s death immunity can fail in this fight if you receive a knockout blow before you hit the 12%. Happened to me last raid, I’m pretty sure. I assume there’s something buried in the dozens of nodes about what this happens. But who knows, maybe not. I’m not reading all that **** either way.
Can someone explain why this isn't the correct answer? I must be missing something. You're going to die after your first fight (which it looks like OP did since he's not at 100-88% health so it wasn't the first run), after which you won't have any charges and this won't gain you death immunity unless you then defeat an opponent, in which case you'll get one, but then will die again on the next fight and you won't have any for awhile again.
He means Dread. @willrun4adonut has explained it already; but let me give it another go:
You start the quest (not each fight - the quest!) with one Dread; and you gain one Dread each time you defeat an opponent.
Any time you would die, you consume one Dread to generate your Death Immunity buff.
In Raids, you can only do that once, then unless you happen to be the person who defeats the defender, you won't have any Dread for subsequent fights; so you've got nothing to consume for your Death Immunity.