#of course theres also the option of he goes to hell and gets super involved in the admin of it all.

[fandomwandererer]

ok i m aware its unlikeley people know the rerference but the spirit of letters thing makes me think of terry pratchetts going postal. and so i propose that there is an expy of moist von lipwig just.. extant in this universe, going around reforming dying institutions. either in the spirit world just so he gets to help the lost mail or in the normal world and there are several significant letters being delivered to ichigo and co that were sent when they were much, much younger

Fandom-blind AEWIAM brain-rot from my subconscious.... I have no idea if this even fits.

A pile of paperwork has lingered un-filed long enough to gain sentience and challenge someone for their job. (In my dream it was the postmaster-general)

Yamamoto himself is too much of a crotchety old bastard to be bullied by mere paperwork, but stuff gets lost in the Gotei-13 all the goddamn time and sword spirits will generate out of the weirdest places so I absolutely could see an abandoned archive or lost collection of mail or other forgotten clot of information turning into a spirit and bonding with a human to avenge its neglect. The sword's name is probably a pun on papercut/paper-cutter

Something similar happens in the fic where the artificial intelligence of a massive archive bonds with a human soul on accident and then they are suddenly deified by the prayers of millions of children using the AI to help with their homework:)