Where else would contemptible people go wreak havoc on their way to the Hell they all deserve? Carthagnion, definitely. She drops the Lord Mayor off at the temple of Abadar and appears there by Dimension Door (from a staff). 

She's Mind Blanked, but not invisible. Most people flee from her in terror and that's quite useful for riots. She looks very, very dangerous.

....mob's come and gone, but it's worth staying a minute to collect the bodies, as the archmages will want to raise some. She heads in to do that.

... that's Montero.

Reports are that she defected from the Thrunes early enough to actually count for something, although in his mind it didn't count for much more than having been unusually prescient in predicting their defeat. Well—less prescient than him, maybe, but moreso than most people. He hadn't expected her to have any real loyalties at all, or even the mental slot where a normal person's loyalties would go. Not that he had much confidence in his model of her at all, but—she was someone he could imagine himself having become if he'd spent another decade in Cheliax and somehow survived it.

Of course, that was before he learned that the immortal archmage who was also her mother is still around and running Cheliax. Given that, there's an obvious guess about whom she really works for, and he doesn't trust her either but they are probably in this together.

He'll land in front of her, then, and drop his invisibility.

"Lady Montero," he says. (Her title of 'paraduchess' has been abolished.) "A pleasure to finally meet you face to face." That might even be true.

She can't truthfully say the same, not that she ever pays particular attention to whether things she's saying are truthful. "Riudare." He would probably win a fight. A fight would be wasteful and stupid, not that that stops Iomedaens. "I will confess I was under the misapprehension you were these peoples' bodyguard."

So his deception didn't fool her, which means it didn't fool any agents of Hell that might still be around and he should definitely drop it.

"I was, among too many responsibilities. I'm not looking forward to the failure analysis even if I can mostly predict what it will say." He doesn't see the need to defend himself any further than that; she won't care. "I was under the misapprehension you had retired to Vudra." Not as of seeing her, but he had been, briefly; let her think her deception worked.

(He might not actually win a fight; he spent most of his spells fighting demons and most of the rest on the too-late attempt at a rescue. He's not going to start one regardless.)

She smiles broadly for some reason. "Retirement didn't suit me. I want to check on Citadel Rivad, if you have matters here under control."

"I think I can handle things here, yes." He reaches into his bag, takes out a mirror, and offers it to her. "If you're professing to work for the new regime, call me tomorrow; we ought to share intelligence on who's been instigating this mess." He's not actively maintaining his spy network in Cheliax anymore, but there are still plenty of people in the city who owe him a favor.

"Your people should pick up your stupid little girl before someone less Good does it." She takes the mirror, and Dimension Doors out with the staff again.

He assumes she means Valia Wain. She's not a part of the hierarchy and he wouldn't be the person to deal with her if she were, but—he has a warrant from the Archduke to enforce the law of Cheliax; he could probably arrest her for inciting a riot if he wanted to. He won't, but if it's as urgent as Montero thinks—and it probably is—he could find her and get someone of less ambiguous allegiance to do it.