You saw Tempest in the library with Moon Dancer and Chancellor Neighsay. She is discussing with Neighsay. If you look closely in the scroll, what do you think is their topic?

Erectile dysfunction

7661666
Doesn't look like it. If I looked closely, I saw a horn-like thingamajig-y

7661668
Just kidding yeah that is a horn I agree. Maybe they are looking for a method to restore her horn

7661666
You know what...*sighs*

Horn healing spells.

If I had to guess I said it was some sort of regenerative spell or plans for an artificial replacement.Because if you read other books with magic, you’ll see that her horn still works but when it comes to the broke part. It has no way to be let out in a controlled path.