If me and my opponent are both at 1 life and I have a {Blood Artist} in play and he sacs a {Soulcage Feind} then what happens? who dies?
even without the artist who dies?
Who's turn is it?
Without the artist, you both die. With the artist, APNAP order would mean the active player puts their triggers on the stack first, then non-active player's.
So he dies?
Right. And if it's your turn, you both die because the Fiend's ability will go on the stack last.