I love this AP but think Queen Elvanna needs to be made into a more interesting villain so added a whole new backstory.
What if Elvanna is actually possessed and being controlled by the old queen Tashanna (yes very Final Fantasy 8). Here's how:
Many years ago Baba Yaga "gave birth" to two daughters in her mission to create the ninth queen of Irrisen. As they grew these sisters, Tashanna and Elena, became very different. One fair and the other dark. Whilst Elena was the most beautiful, Tashanna was the most powerful and more drawn to her mother's secrets. So whilst Elena moved to her mother's thrice tenth kingdom and became beloved of even the nymphs, who called her Bellaluna. Tashanna was crowned queen of Irrisen.
But during her 100 year reign she grew suspicious of her mother's plan for her once her time was finished and so hatched a plan to fight Baba Yaga on her return. She discovered the Torc of Kostictichie, containing the bound soul of the demon lord of misogyny, Baba Yaga's mortal enemy, giving her control of the demon lord and his forces to supplements her own, But she lost! Baba Yaga proved too powerful and she was pulled from her throne like so many of her sisters before her.
However, she was the first to actually impress Baba Yaga. And so after tormenting her and brutally killings her generals to ostensibly make an example of her, so didn't consume her power and leave her a husk of a crone queen as she had to her sisters. Instead she allowed her to live and explore the multi-verse gaining further power with one rule only. Tashanna was banned from ever returning to Golarion, or even the same solar system. To ensure this Baba Yaga cast a powerful curse which pulled Elena the fair from the Thrice Tenth Kingdom and bound her to the land in Golarion, preventing her, conversely to her sister, from ever leaving. Whilst Elena remains bound to the land no magic in all the multiverse is strong enough to allow Tashanna entrance to Golarion again. But Elena was made immortal and only able to manifest in areas where the ley lines of Golarion cross. Only if all of Golarion were in eternal winter would she wither and die and the spell be broken.
And so Tashanna left Golarion and grew in power as she explored many worlds and indeed took many names, But she was never one to take no if an answer and as her power grew, so did her bitter resentment of the one thing she was denied, Golarion.
Many many years later the 14th Queen of Irrisen, Queen Elvanna grew close to the end of her 100 year reign and, like Tashanna, sought ways to combat her mother when she returned for her. She found a journal of Queen Tashanna confirming her suspicions. But this was no mere journal, Tashanna had cursed it allowing her some contact with its reader, if meager. She taught Elvanna a powerful ritual of binding to use on her mother once she returned but it required another enfused with mythic power. And so Tashanna guided Elvanna to another soul she had been manipulating through dreams and visions. Rasputin, son of Baba Yaga. Together they bound Baba Yaga within a doll leaving Tashanna free to enact the next part of her plan.
She revealed the mystery of Irrisen's eternal winter to Elvanna and a way to amplify it over all Golarion. And so as Elvanna began opening winter portals around Golarion in her ritual, Elena the fair weakened along with Baba Yaga's spell allowing Tashanna to take more active control over Elvanna. At this point she has managed to pretty much seize control of her mind and hopes to take the throne herself of the eternal winter land Golarion will become. Tashanna the dark will return!
