A Pandemonium of bones. Such monsters are only vaguely referenced in legends, and in a way, it is the most powerful kind of Undead; its existence is only theorized about. As its name may suggest, it generates armies of skeletons. It is an enormous castle of walking Undead monsters. It is larger than castles of large nations; describing it would be easier by comparing it to a mountain. There is likely not an A-class adventurer party or even an S-class adventurer who would want to face this monster, as they might starve to death before the battle comes to an end.
Knochen in particular would be a particularly problematic foe. Master gladly offered it a countless number of bones of the Demon King, thinking of it as spoiling his pet. Thus, some of the bones cannot even be damaged without Orichalcum equipment. Honestly speaking, I believe that Knochen could perhaps destroy the Mirg shield-nation and occupy the capital city on its own. After all, it would be capable of dispatching a countless number of Skeletons as an extension of itself to watch citizens and dispose of them if need be, and it would become a strategic location to hold. Even if A-class adventurers capable of sundering mountains and S-class adventurers even more powerful than them were to appear, they would struggle in a battle against Knochen. Monsters like Knochen can often be defeated by destroying some kind of core at their center, but this does not apply to Knochen. Of course, Knochen is specialized in defense and generating numbers, but it does have flaws. It has limited attacking capabilities and few methods of attacking. However, as a Rank 13 monster, there is no doubt that it could overwhelm A-class adventurers through brute force.
