Death Cube (デスキューブ, Desukyūbu) is a Darkness ÄRM which locks a person inside a translucent Rubik's cube. Anything placed inside cannot be taken out without solving the puzzle. The box is connected to another space, and if you make a mistake in the puzzle or break it forcibly, the contents inside will be blown to another space and disappear.
Compensation ⇒ Whoever solves the puzzle and releases the contents will be sent to a different space instead and die.