This is the function that causes Marisa's `Divide Error` crash when
called during a 4-frame window during the end of certain patterns.
Just like with Kurumi's division by zero, it's just as undefined here
what should happen instead, and any possible fix can only ever be a
fan-fiction interpretation of the code. And since the community will
have an easier time understanding and debating a C++-level hack instead
of an ASM-level one, it makes sense to first decompile this function…
…and document it, which is actually much harder!
Part of P0189, funded by Arandui and Lmocinemod.
nmlgc