Anasteya is
The Forgotten Queen, right?
Or at least
related to her (an apprentice, a daughter…)
I mean the clues are all there, her hiding her past, using magic (Alchemy) and it’s too much of a coincidence that the demon appeared to “help” right after Sunny rushed to warn her, and by Amaya description,
that is a characteristic ability of the queen.
BTW being called
“little prince” also gives contributes to the theory
Also... I have to say I’m liked the lore references/inspirations, although I can’t assume they are on purposed

, many of them are from things that I enjoy, like:
Tevinter Magi Empire (Dragon’s Age) on Nyssian Empire and its destruction Númenor style (Tolkien), although it can be compared with Sundering (WoW) too
High Elf Queen Azshara pact with demons (WoW) on Ael’Vanwa Tári
Draes Nythara having Dalish (DA) and Scoia'tael (Witcher) characteristics