You know what's a creepy thought, is Ludinus' interest in Essek alongside their similarities. It seems like the Dynasty's system and religion turned Essek into who he was (Matt hints that even Verin knows this but has hope):
"He understands why his brother is the way he is, but he also believes a lot in the Dynasty, and the faith that the Luxon and the whole idea gives and he, like, partially believes it?"
Ludinus is a heretic from a culture who still worships Corellon despite their city's fall and the empire's religious ban, and he's specifically noted to hunt the Dynasty for secrets and weaknesses. He probably knows exactly what to look for to find a hidden apostate in a religious society, like knows like.
At peacetalks Essek was certain that the Dynasty would kill him, but that he could lean into "his resources" (Ludinus) for protection, and to put it mildly, Essek's not an optimist. It's almost like Ludinus sees him like an apprentice and Essek knows it.
How long do you think Ludinus has had an eye on Essek? Caught a glimpse of him in Kryn diplomatic envoys (which Essek said Den Thelyss invests in) Ramped up efforts after hearing news of Essek's father dying, in a way that we see Essek clearly blames himself for? Going really out there, he could even be the source of Essek's 22 int, giving him a tome of clear thought.