During the Kingdom Hearts Orchestra performance in Osaka, the series director, Tetsuya Nomura, made an appearance, and revealed some information about the upcoming DLC for 'Kingdom Hearts III':

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First off, a new trailer will be released next month, and the DLC's release date will finally be revealed (presumably with the trailer). Also, two new difficulty modes have been announced, called Fast Pass and Black Code. Fast Pass is an extremely easy mode that allows players to defeat enemies with one hit. Black Code, on the other hand, is an extremely difficult mode, allowing players to adjust difficulty to make things as hard as possible (ex. no healing). In addition to the difficulties, Photo Mode was revealed to get some additional features, allowing players to choose a location and pose with different characters, while also providing the player with the ability to include background effects. There will also be a Slideshow Mode, allowing players to create slideshows with their photos.