Shigai
The shigai were monstrous entities that roamed the passages of the Corpse of Niseki. They were made of Nisekite, and made terrible noises as their organic bits gurgled and their stone limbs scraped against each other.
The shigai took on a myriad of forms, with each one different than the last. Early Nekrosakans called the shigai "lithic carnites" due to the similarities in their monstrous, unique sculpts.
It was unclear where shigai came from precisely, as well as how they were made. Nekrosakan miners that ventured into the Niseki Caverns to scavenge nisekite always saw these monsters emerging from the deepest, darkest, most unexplored recesses of The Corpse.