This article contains plot or progression spoilers. Continue at your own discretion!
Parasite is a location that can be accessed through the Beneath or Our Dull Vessel through the Parasite Plane (only if incoherence is high/you are wearing the Hunger mask). Parasite takes form of a large, life-sized parasite board.
Initial Visit
Entering through the Beneath, you will enter a small pathway, going along the path you can find a Calm Piece, a game piece of the game "Parasite". Greeting it, it will say that it is quiet.
Continuing down the path, you can enter another room, with two large Pieces on either side of a Parasite game board, the Smiling Piece and the Many-Eyed Piece, who represent Gakvu and Miltza respectively. On one side of the board is Cavik, Akizet, and an interactable effigy, on the other side are two Containers and a Golem. Using the Unity ability on the effigy results in the Smiling Piece complaining about it leaving the board mid-game, and the Many-Eyed Piece saying it counts as a death, with the smiling piece objects to.
Interacting with either piece will allow you to talk to them.
Continuing past them brings you to a giant Parasite game board which you can walk around in with many game pieces representing characters in the Call Research team or met in Recollection: Collapse.
Going past this room, it will bring you to another big room with 2 gates, entering the one you can see first, it will bring you to Jokzi Ozo, in Isabel's room. Entering the other one will bring you to Our Dull Vessel, which you can go to and from from.