Why'd that comic-writer bother creating a layer of jargon for a straight-forward concept? All we're talking about is death of a loved one done so obviously that it ruins readers buy-in for the male protagonist's motivation. It was done too quickly, with little gravitas and not enough lasting impact.
In BG3 it'd be like Tav saying 'Goblins killed me wife and kids. Raagh! Oh? Hello Minthara...
I think you kind of answered your own question. What you conveyed in two sentences can be instead conveyed in a brief, evocative phrase or even word. It's why any jargon gets created. The fact it still gets used shows that in general people thought it was a good shorthand.
I don't know who Pandirna is, but as far as where Hags come from its stated in the monster manual that hags are made by a hag eating a newborn then birthing a copy of that newborn who will become a hag when she comes of age. So since we don't know what first darkness actually is, and it's too vague to even infer much, we know that she's lying. Even for those who don't know the lore, believing her seems like an unwise choice.
