The only death I've gotten all the way from level ~90 to 97 was making the mistake of leaving my fire resist negative and using a merc with flickering flame to bring it back up to 75%. Which worked great and took barely any damage from anything with 20 blood oath and max resist. And died in a single volley to a group of P8 TZ 96 tier 5 herald fire skeleton mages that killed my merc, removing my fire resist. And if my math's right on average 14 mages at +50% and the herald at +250% deal a combined average ~5600 fire damage per volley, which after -20% resist and 43% blood oath would become ~3840 hp. Even that was an easily avoidable death if I had just bothered to put my demon in front of me.
and granted thats out of thousands of games and not playing even remotely carefully, teleporting into dolls / souls all the time and not caring, etc etc
i always spam death mark + sigil leth , the only time they get scary is dolls + amp cursed ( nothing can survive from a pack of doll with extra strong , extra fast , cursed
)