Based on a read of the recent ruling re: The Harry Potter index, the summary of the ruling that I read commented that the creation of the index was fair use as a transformative work, and that the problem was that the entries had too much of the original content. (Large sections of text placed verbatim, if I understand correctly.)
If I view character creation and power code software as transformative of the original books, and have abandoned the GSL for general copyright law, and I am clear to use my own text in the power cards, and do not use any art or trademark symbols, wouldn't that put the Character Creator and Power Card software clearly in fair use?