well so far the compilation of VII has proven me right on what rules to use for Yuffie and Tifa, the trailer for X which comes on "The Spirits Within" clearly pronounces Tidus as Tee-dus unlike the american comedian Titus (Tie-tus)... sure those names may be made up but it has always been clear which pronunciation rules to use for which names as most names in the FF series are generaly Japanese, German, & English in nature... now as for Quistis what languages pronunciation rules gives you Kis-tis because that one i always thaught was English (UK) in nature, i could be wrong due to the uniqueness of that name and it could possibly be French... oh, if Tidus was pronounced Tie-dus wouldn't it be spelled Taidus...