Light Novels/Volume 12

Kumo Desu ga, Nani ka? Volume 12 was released on January 10th, 2020 in Japan and it's English translation was released on July 20, 2021.

Synopsis
1st version:

Whoa, war's broken out and it looks like it'll be this world's deadliest. Yeesh. The Demon Lord is doing her best and it looks like the only one who might be able to stand in her way is some hero named Julius. If I'm going to help the Demon Lord figure out this world peace thing, then he's gotta go down!

2nd version:

THIS COLD WAR JUST WENT HOT!

This is a special spider field report coming to you straight from the human-demon border where a massive battle has erupted! The Demon Lord is finally launching an all-out assault on the fortresses guarding the human realm’s frontier and has committed hundreds of thousands of soldiers for the attack. On the other side, the humans are putting up a stiff resistance! All signs point to a bloody day of fighting for both forces—though that’s kinda the point, y’know? Hopefully the hero comes onto the battlefield as planned…

Chapters

 * Observations by Future Historians: Prologue
 * White 1
 * Sanatoria
 * Huey
 * Ronandt
 * Kunihiko
 * Asaka
 * Aurel
 * Merazophis
 * Phelmina
 * Wald
 * Sophia
 * Wrath
 * Hawkin
 * Agner
 * Jeskan
 * Bloe
 * Balto
 * Yaana
 * Julius
 * White 2
 * Observations by Future Historians: Epilogue
 * Afterword