Cinjinn, while Sorrow (the entity) was incorporated into the AI to make Omega & does have the books info in him, I think all of Sorrow’s knowledge is also in Declan. He can’t access it as easily as a computer can & doesn’t “know” the info/spells until he’s prompted to think or try to remember them. There’s probably a language spell in there somewhere.
Rynedee, you maybe right, although, if I were Omega, I’d still want to know. Monkey curiosity, if nothing else.