I don't have a really good renaming for Invidia, although the provisional name is Întradevăr (similar to "In truth" in Romanian).
Its backstory has been extensively rewritten to examine a specific political hypothesis. The idea is that the Core has always been fairly anti-Vistani, treating them as second-class citizens even if they fear to outright abuse them. Întradevăr asks the question of "what happens when you give a landless people a land of their own... and they end up just as miserable as before?"
Aderre's backstory focuses more on persecution by non-Vistani rather than framing her mother Isabella as expelled by Vistani.
Aderre fled to Întradevăr in order to escape persecution of her and other Vistani descendants by non-Vistani in neighboring domains. When she assassinated Bakholis, she was able to establish her own state, making it the first time a Vistani actually became part of the ruling class. (Although admittedly, Gabrielle is only part-Vistani.) The dusky forests and beautiful rolling riverways of Întradevăr initially held out hope of a free state for Vistani to travel and roam as actual right-holding free people in their own land.
Gabrielle's whole justification for her rule is that this is a land "by Vistani, for Vistani", and foreigners are not free to mix and mingle in Întradevăr. The Vistani families live simply, and rustically, as nomads. Întradevăr thus plays to a narrative of ethnic pride and solidarity, with a small roving Vistani population distrustful of outsiders and rejecting their "corrupting" influences of landowning, industry, taxes, and military levies.
Aderre's inner contradiction stems from the fact that she has to adopt some of these trappings of power, thus distancing herself from her desperately yearned-for Vistani roots. Ethnically, too, she is secretly separated by her half-blood parentage. She is also a landed national ruler of a nomadic classless tribe, further underscoring her own outsider status. She rules with a narrative of Vistani-first, but is herself only a tenuous claimant of that ethnic birthright. In her interpersonal dealings, she is dependent on foreign non-Vistani missions and traders for her status, because her own lack of a family group leaves her otherwise unsupported in a culture of family ties.
Somewhat in keeping with her canonical relationship torments, Aderre can only trust herself to form the briefest of dalliances with local Vistani. She knows that any protracted period of contact will expose her as a fraudulent claimant to the Vistani ways. Her only other avenue of longer-term companionship is with foreigners, like the Gundarakite leader Szerieza and the wolfman Matton, who are the very targets of scorn and suspicion for the Vistani-first nation she herself constructed.
And quite separately, Aderre has to get her hands dirty from time to time in balancing out the resident Vistani tasques, in case any of them grow too powerful and refuse to reck her rod.
"This land was meant to be safe haven for us. They overthrew the Prince and the Nevasta took power."
"All Tigan and Vistan rejoiced, for she said now our peoples have a land! But we went and soon there was feuding and rivalries and bloodshed. Only this time, the hands of our own brethren were the ones wielding the knives."
The guy closes his eyes and breathes out raggedly.
"Such is the lot of fools. Given a haven for themselves, free from the hatred of strangers, they rush to find new fiendish methods of torment, visited by themselves, on themselves, for themselves."