If the scripts Yosurako uploaded don't work you could try the attached DLpy to download the JSONs for the missing characters. I don't know what the DLpy errors mean so I open the JSONs in a text editor, such as Notepad++, and look for errors. If the file has the word 'error' in it, either the character isn't released yet or the DLpy code is flawed. Don't use these files or you'll have the problem described in post #783. The presence of the scenario_path, resource_directory, is_r18, title, and summary entries are signs that the file is likely functional. Post #762 shows examples.
Edit 1: Changed [Wind Rider of Arbitration] Perbia's name to [Wind Rider of Conciliation] Perbia, matching the name shown on the English wiki.
Edit 2: Updated to include the DMM files for [Memorial0011] Alyssa and [Memorial0012] Frey and both versions of the DLpy script. The previous DMM files are on post #793 and the newest troubleshooting guide is on post #797.
Edit 3: Updated to include the DMM files for Vishnu HA, both DLpy scripts, and the 0_download_json script. 0_download_json.py has been modified to download the JSONs for [Elegant European Flowers] Selene and [Cafe Romance] Amanor.