I imagine the best way to do this will be whatever quickly evokes a large amount of highly-correlated tokens for the kind of fictional character the user wants

I imagine the best way to do this will be whatever quickly evokes a large amount of highly-correlated tokens for the kind of fictional character the user wants to see in the story. In other words, the completeness or scientific rigor of the original categorization and naming is irrelevant, compared to its consistency and presence in the training data. In some cases, the most straightforward approach might be to name a particularly popular character by name.