I've not played through Runelords, but found a couple of other threads (links if you'd like to take a look, both of these are spoiler-y thread #1 thread #2) that pointed to the following paragraph in the Anniversary edition (page 65):
It’s possible that Nualia escapes death in this adventure—in this case, she makes her way to Magnimar as soon as she can to rejoin her allies there. When the PCs confront the Skinsaw Cult in Chapter Two, they should find evidence that Nualia has visited them recently, but her exact role in the rest of the campaign is left to you. She could end up aiding Lucrecia’s efforts against Turtleback Ferry, become one of Mokmurian’s allies, join forces with the Scribbler, or even make the pilgrimage to Xin-Shalast to pledge her service to Karzoug. You should advance her levels as appropriate to keep her a powerful enemy (three levels or so above the average party level)—consider giving her levels of the divine scion prestige class detailed in Pathfinder Campaign Setting: Inner Sea Magic. She could even complete her transformation into a demon— this ritual is detailed in full on page 45 of Pathfinder Campaign Setting: Book of the Damned II: Lords of Chaos. Nualia as a half-fiend, or even as a succubus, would certainly make an even more dangerous foe than a mere wayward aasimar!
Not finding much mentioned for "T." but that might give you some ideas or starting place for "N.". Having not actually played it, I'm not sure what kind of builds fit their backstories.