Elven High Magic is the stuff of legends, an Art so powerful that it could - and did - sunder continents and slay gods, and more often than not consumed the life - or lives - of those who tried to use it. Due to the elves' reckless and irresponsible use of it, Mystra herself did indeed forbid its use. According to lore, she either slew all those who knew how to use it, or scoured such knowledge from their minds.
Thus the horror in the eyes of both Xan and Liia.
Xan's eyes shift to see who might be near, who might have overheard. He locks eyes with Aiwe for just a moment, and his next words are for both of the young women. "Stella, there are those who would kill to have this tome, in order to attempt to pry arcane secrets from it. And they would do much worse to get their hands on you for having scribed it."
He exchanges a glance with Liia. "I have no idea what this means for you, Stella, or how you could know any of this." He taps the page. "I would tell you to burn the book and never think of it again, but it seems you may have no control over that." He takes a deep breath. "In my home, Evereska, there might be someone who can understand what's happening, who can help you. I can take you there. I would insist on taking you this very instant, but for the fate of Baldur's Gate; you're too important to what's happening here, and stopping the war."
He closes his eyes. "I pray- No. That is too risky. I can merely hope that in this I am not making a huge mistake."