I don't think Narcissa's DMC is bugged. There's a lot of attacks that pierce armor and magic in the game. Narcissa's just a bitch.
So, yes, if you get Narcissa to 0HP and she hits you with DMC, she can one-shot you with it, particularly if she's an Angry Kitten
If you're in Shadowbound when this happens, you get the Game Over.
And yes, you have to break Narcissa's seal in front of her for this build.
OMG the Eldritch Tomes.
I decided to make my Arcanist/Wizard very proficient in using the Magic Staff. It's taking a LONG time. I get about one Proficiency point per level, so it's hard to tell if there's any noticeable difference.
EDIT: If anybody's interested, I'm currently battling Katrina's Hollow Swordsman with my Staff of Dawn. The Staff may be why my MATK is now 15 in Katrina's Realm. ANYWAY, my ATK is still at 1, so I can't hurt the Swordmsn with regular attacks and the Swordsman can't hurt me. Twice I've heard the audible sound effect that indicates that my proficiency has gone up. I'm about to set a remote control on the spacebar to keep the battle going and then mow the lawn
EDIT 2: And that's how I gained 20 Proficiency in one battle.
Curious... seems like all the Lost that have a discernable gender are male. Didn't Llavanya ever consider selecting a female champion who might be more difficult to seduce? Doesn't seem like a great plan...
Sell them to the Reaper for Foreign Soul Shards.