Xolotl here throwing something out about the letter in wicdiv #28. Spoilers for wicdiv 35 and 36.
Given these issues, Ananke’s letter in 28 is almost certainly addressed to baal. In 35 we see that Minerva gains all of Ananke’s memories. It seems unlikely that a letter expressing her intent is necessary (though this is YMMV). Next, in 36, we see that minerva is well aware of her murderous purpose and of the existence of persephone as a god and not some external demonic entity.
Ananke’s letter, however, states her intentions and leaves instructions behind (which Minerva would not need if she absorbs ananke’s memories either pre- or post-death) and also calls Persephone “the destroyer”. She is clearly speaking to someone in the pantheon who is not Minerva.
And since Baal is under her thumb with the sacrifices, it makes sense: she’s sending the letter to Baal. She even mentions years of sacrifice at the end of the letter, which feels like a real dig at him, another way to pull his strings.
(Endnote 1: If I am correct it makes it interesting that she cries while writing it; it gives me the sense that she might not have just been confronting her mortality, but also feeling something genuine towards baal? Hmm. I suppose we will see. I somehow felt like the darkness killing baal’s dad was fishy and ananke-orchestrated rather than organic)
(Endnote 2: On the other hand the child sacrifice feels like something Ananke would not throw into the mix lightly; there is so much room for something like that to backfire (scandals, discovery) and outweigh the possible benefits of it as manipulation fuel. I feel like this means the child sacrifices do occur throughout each recurrence in one form or another? It sure seems relevant when we look at 1831. Could fall in line with the thematic idea of the adults stepping on the youth, a la David to Jon or Ananke with the Entire Pantheon)