Some of the locations in Hong Kong are near-faithful representations of actual locations.
Su Yung is referred to as The Sorceress in the credits. In the original version of the movie, she is called "Madoushi" which translates to sorceress.
Dubbed in English and released as 'Cardcaptors: The Movie' when the 'Cardcaptor Sakura' series aired on American television. As in the series, which was heavily Americanized and stripped of many of the more unique or risqué elements of the Japanese version, the movie shown in America featured renamed characters ('Sakura Kinomoto' becomes 'Sakura Avalon;' 'Yukito Tsukishiro' becomes 'Julian Star,' etc.), re-done music, and a tremendously altered plot. The result was one of the worst and most widely reviled Japanese-to-English transitions since the importation of anime to the states, in terms of faithfulness to the original. Due in large part to a heavy backlash by American fans of the original Japanese version who resented seeing their favorite show (one which dealt with many more complex issues than the typical Saturday Morning cartoon) turned to depth-less Americanized kid-fodder as 'Sailor Moon' had been several years earlier, Pioneer Entertainment (now known as Geneon) thankfully released the American DVDs of both the series and film in their original unedited Japanese language versions.
Madoushi, the ghostly soceress who pursues Sakura throughout the movie was never identified by name.
In a somewhat unusual collaboration, Madhouse Studio which did the bulk of the animation for the film teamed with the famed Studio Ghibli to do the many special animation effects the movie required.