Work being done on deciphering the languages in Mushoku Tensei

I just saw a video on YouTube about deciphering the languages in the anime adaptation of Mushoku Tensei: Jobless Reincarnation (無職転生 〜異世界行ったら本気だす〜). This is just a quick note for those who are interested in how to go about this.

After a quick search on Google, it seems that people have figured out the technique used. It is really the same as Violet Evergarden (see my Tellsis translator here and the substitution here). The words are translated into a real world language that is not Japanese or English (too easy to figure out), then a substitution cipher is used to replace the alphabets. Names are not put through the substitution cipher. Finally, the output is presented in a unique font.

For the Human tongue in Mushoku Tensei, that real world language is Basque (although English is also used, such as the "magic book" that Rudeus first read as a kid). For the Demon-god tongue, it is Zulu (with some Swahili). For Beast-god tongue, it is Haitian. For the substitution cipher, vowels, if switched, are usually switched with vowels so that they can be read. Accented vowels may end up being replaced with composite vowels. Consonants are switched with consonants, and sometimes with a double consonant (like sh, ch). This person on Twitter, 双倉, has quite some pictures and such on the work done to decipher these three languages. Below is an example taken from Twitter.

Looking forward to someone consolidating this eventually... I am a bit busy now with setting up that new (used) server now...

Update: You can see a table of the letters in Demon-god tongue here. (Video is in Mandarin, though.)

Update 24 July 2022: Found this post in Reddit with a nice table to show how the writing system related to our alphabet.