Support the official release if you can: https://www.audible.co.jp/series/<物語>シリーズシリーズ/B08WH8LJF5
I made the srt files so I can use them on android with vlc media player, since it doesn't let you use subtitles with m4b.
For the audiobooks I used [AgPa1t](https://nyaa.si/user/AgPa1t)'s files and the Japanese Audiobooks Collection (https://nyaa.si/view/1616763)
I used AudioBookConverter to turn them into single m4b files and add covers: https://github.com/yermak/AudioBookConverter
I used ffmpeg to convert the m4b files to mp4 and I normalized the audio. I also used it to create mp4 files from the m4b using a black image.
I used youtube to sync the book to the audio and exported as srt (It was easier than using [this](https://github.com/kanjieater/SubPlease))
For the epubs I used lovefool’s files: https://nyaa.si/view/1768037
Since the audiobooks have 上, 中, and 下 I used those versions. I found them on Z-Library.
I bought 戦物語 myself.
番外編 includes 佰物語オリジナルドラマCD シナリオブック and 化物語 アニメコンプリートガイドブック
There is no epub version of 混物語 I can find and I don’t want to buy it.