Changing the subject, I'd just like to think a bit more about how incredible another face of the coin is:
- The Night Prowler: As long as you are outside of private property and within a town or city, nobody will question your presence and nobody will be able to find you if you do not wish them to. For non-human population centres, will work if it's not completely unknown for humans to be present, or if you are disguised as that species.
Just imagine how amazing that would be for an assassination campaigns in skaven warrens or greenskin settlements. I think Matilde would be in danger of earning Khaine's attention and favour if we fully exploited it. Think of the campaigns of terror she could launch with this. Even in the rare private spaces those species have, in almost all cases she should be able to exfiltrate from those locations into public places, and then vanish from awareness. Mathilde could quite openly go around killing people on the 'street' then ducking around corners and effectievly vanishing. Or sniping people from a public vantage point once we get her a longarm. Brutally Cunning indeed.
With this I'd say we should hit the City of Pillars immediately and launch a decapitation and sabotage campaign. We could turn the place into anarchy in days. Imagine how dispiriting a literally impossible to find saboteur and assassin would be. At worst, the important skaven wouldn't dare to leave their personal chambers and paralysis would ensue as we murdered their couriers. At best we'd be able to kill them all, blow up their workshops, and kill their pets.
And one of the best bits of this is that it will seem like we've just developed an incredible mastered version of Take No Heed.
I still think there's a very good chance that this a goblinoid civil war, and we're just taking advantage of them exposing themselves, so there are no orcs between the Citadel and Nar.