I turn down my master volume to 0, then kill the goosefoot
Floor 882 lies a portal, there is no door past this floor, and it is a runthrough of floors 1 - 881, after the runthrough, you fight the supreme lord of darkness (Power level: Multi Galaxy)
After you defeat this darkness lord, you are teleported to floor 883, there's no going back now.
I use the stairs in the purgatory version of the floor.
Floor 884 has the exit to floor 885 locked and the only way to unlock it is in purgatory (to which only I can travel between purgatory and the living world), there's also the fresh corpse of the last person to fail the floor.