Xestris

Story
From the brief times that the group has observed her, very little information is learned but some small tidbits are evident. First, she has the total confidence of her boss and a more carnal one. Second, she has a pretty good grasp of business and trade affairs. Third, she keeps her distances from both the events and the sexual debauchery around her.

She has a brief appearance at the end of the Chapter 3, when she is spying on the Fucklord and his pet in The Tower. The scene is ambiguous enough that it's unclear is that is her only goal, but strongly hints that both Incubus Kings are aware of the existence of other realms and that they visit them. The goals of that visits are unknown for the moment, but there are tensions between them (she describes the Fucklord as an annoyance and she is looking for something/someone that gets rid of him).

She also observes Simon and the party during their first expedition into the Tower, expressing her concern over Simon's potential to take unexplained "final steps" very quickly.