Lol even if you did survive the nails ifrit would still do hellfire.
In ifrit hm i casted healer lb3 during a wiping hellfire.
An interesting thing is that ifrit will cast 2 hellfires just to make sure that your raid is dead due you not killing enough nails.
I was like woot i rezzed everyone thru that! Must be a glitch or something, then seconds later.
He jumps up and casts a second hellfire shortly after.
Best bet would be for tanks with buffs up.