You need to have Eye Head to see in the void. You will see a clone of headdy without a head. With Mint Liquid. It is called Header. Watch Header so that header can't move. If you look away and header catch you. You'll get jumpscare. You need to find a rope thats brings you out of the void. Shoot your head to the rope and They will pull you up. The huge hole will be in 9-7. Jump down to be on 0-0 Dlc tho.