What is the safe hp range for not getting oneshot

My Jugg in last league had 9.5k life and 9 endurance charges. I still got one shot on occasion on deep delves if I didn't get outta the way quick enough on the telegraphed moves with crazy (multiple added ele and penetration for example).

So I think the answer that apart from some of the crazy hardtop to acheive and maintain, 100% of the time anyway, immune builds (if they still exist this league) then there isn't really a completely safe number.