Spoilers: I'm going to stick to Basics for a while, even though they contain spoilers...
AKA: no nicknames
Looks: 6'3", blue hair, purple eyes, troll-demon-elf-goblin.
Character: Impish, brilliant, strong-minded.
Special skills: Trond shaman and Shinou priestess.
As an adolescent, Ilya got it into her head that true reconciliation between Trondheim and Shin Makoku required a spiritual reconciliation between Trond shamanism and the cult of Shinou - therein lay the key not only to lasting peace, but a soul healing of Trondheim's meek demons and alcoholic elves and ghost infestation. Her father and Lady Alana considered her point of view heresy, especially when the willful girl joined Shinou's temple as a priestess. (The Tronds found the cloistered virgin bit particularly offensive.) Her family disowned her, save Ted, who also chose to live 'down below'.
Ilya and Aldrich collaborated on a shaman-Shinou theological synthesis. She helped Aldrich bypass Ulrike to discuss troll issues directly with Shinou. Her crackpot theories were finally vindicated in GoT.
Now reunited with her family in Trond Hall, Ilya is heir apparent to Lady Alana. She adopted a treeborn baby troll girl.