Apart from the shotgun, at the end of the battle in Songze, Hachisaku also picked up something from the ground—
[Divine Fetus Blood (Ultra-Epic Material): Blood from the fetus of Hirudinidae, connecting to the essence of blood of Hirudinidae and its fleshly avatars. An extremely rare material, perhaps this is the only piece left?]
This is a small tube of thick liquid wrapped in a transparent meat coat, appearing golden, and the fluid continuously swirls within the meat coat.
This so-called "Divine Fetus Blood" is entirely different from the black blood and flesh on Hirudinidae's body, its aura seems much more sacred, and it doesn't have that disgusting fishy smell.
Because it looks somewhat unusual, it's no wonder Hachisaku picked it up.
Unfortunately, its use is temporarily unknown.
Also, take it to Takamagahara to see if Sister Kaku will have any ideas, for instance, using it as material for the Shrine.