Hi Vanilluxe92!
I've found some code that could be of assistance, that being an older GitHub repo for extracting files from Ougon Musou Kyoku, which can be found here.
The file you've provided seems to match the "fake compression" described by the author and contains the same header ("LZLR") as well, so this may very well work with this repo.
However, I've been trying to compile this repo for a couple hours now, but it seems it's missing a header file that most of the C files use, rendering the part of the program used for extracting "LZLR" headed files completely useless. I opened up an issue on it, but the repo is 4 years old and the user who made it hasn't done anything on GitHub since March, so I haven't got much hope for that solution...
Update: Found a couple more dead ends on Google (here and here), and still no luck on compiling the code.
Sorry I couldn't provide any solid results yet, but I hope this helps a bit!
I've found some code that could be of assistance, that being an older GitHub repo for extracting files from Ougon Musou Kyoku, which can be found here.
The file you've provided seems to match the "fake compression" described by the author and contains the same header ("LZLR") as well, so this may very well work with this repo.
However, I've been trying to compile this repo for a couple hours now, but it seems it's missing a header file that most of the C files use, rendering the part of the program used for extracting "LZLR" headed files completely useless. I opened up an issue on it, but the repo is 4 years old and the user who made it hasn't done anything on GitHub since March, so I haven't got much hope for that solution...
Update: Found a couple more dead ends on Google (here and here), and still no luck on compiling the code.
Sorry I couldn't provide any solid results yet, but I hope this helps a bit!