Urotsuki is a real trooper
Pillars World (柱, Hashira, Pillar) is an area accessible from the north passage in the forest area of the Chaotic Buildings.
This world is very foggy and has a tint of dark green. Many big pillars are scattered around. By going south of the ladders you will see smoke coming out of the walls and a creature that is sucking up the liquid, which highly resembles Onsen-san from Yume Nikki. Chainsawing it will make it stop and bleed from it's eyes. Turning around and stepping away afterward will make it suddenly transform into a multicolored version.
Nexus → Red Streetlight World → Gray Road → Grass World → Green Neon World → Construction Frame Building → Cog Maze → Forest Pier → Abandoned Factory → Arc de Pillar World → Mansion → Deserted Pier → Deserted Town → Chaotic Buildings → Pillars World