She has referred to herself as “literally an incarnation of illicit sex”. That means succubus.
I thought it was a joke about never remembering which material works for which sort of fiend. Compared to things like silver for lycanthropes, adamantine for objects and cold iron for fey, the materials for fiends are less obvious.
We already did. Despite what Chronos says, erinyes in D&D are not incarnations of illicit sex, they’re fallen angels. Besides which, erinyes don’t have Sabine’s polymorph ability.
I’m doubting it. She’s after Nale and the Linear Guild. If she were a player in the Scribble War, she’d be after the genuine OOTS members. And the fact that she’s still looking for Yikyik, who’s been dead since strip #63, says that she’s not on top of the situation.
A case could be made for Miko’s arc being more important than the Linear Guild (at one point she literally had more appearances than any of the other antagonists), but now that she’s gone, the Linear Guild are easily the most important of the remaining subplots. The only other thing that even comes close is the bit with Haley’s dad, and that’s probably closely related to the Guild.