Alright since Nurgle seems to be experiencing a brief upswing in popularity I thought I'd throw a few questions out there.
Eternal Warror VS Instant Death.
Eternal Warrior makes you immune to instant death, /check
All models in the Demon's Codex are Eternal Warriors /check
Feel No pain is negated by instant death /check
So do Demons (in particular Nurgle demons who are all T 5) get FNP against all attacks?