Playing Card Maze is a world accessible from the frowning cube in the Pink Desert.
Features
This world features many floating platforms with metallic walls. On these platforms are playing cards, which can be used to teleport to other platforms. There are many interesting things of note to be found, such as a running boy whose head is always facing the camera, a dancing character named Hambie who will unequip your effect if you try to attack him with the Pencil, and a mural of a ballerina on one wall. One card in particular will teleport you to a small room with many cards dancing around, as well as neon signs of the card suits on the wall. There is one platform with a brown wall and a door leading to a small room with a set of stairs leading nowhere. There is a small chance that upon entering there will be a jiggling face in this room who will take you to the Bloodshot Hall upon interaction.
Bloodshot Hall
Heading down the hallway will lead to what appears to be a dead end surrounded by creepy faces, but heading back will reveal that the path has changed. It will now lead to a cartoony head that can be entered through the mouth. Inside, there are some hooded men standing still by two poles. Using the Seer effect will cause their eyes to glow, as well as revealing the Anti-Seer, a large hooded man standing in the center. Interacting with him will display a full screen image of his face, before quickly distorting into a much more disturbing expression with eyeballs appearing behind him. Kubotsuki will then be trapped in a closed off area, forcing him to use the Box or to wake up to escape.
Directions
Kubotsuki's Nexus → Twilight Garden → Clash of Mutated Forms → Abandoned Pools → Pink Desert → Playing Card Maze