So a good test would be replacing the spell names in the books with made-up spells. And if a "real" spell name was given, it also tests whether it "cheated".
It could still remember where each spell is mentioned. I think the only way to properly test this would be to run it against an unpublished manuscript.
A real test is synthesizing 100,000 sentences of this slect random ones and then inject the traits you want thr LLM to detect and describe, eg have a set of words or phrases that may represent spells and have them used so that they do something. Then have the LLM find these random spells in the random corpus.
