Concepted by Noah Hevey, CAD-designed by Adam G. Cowan this puzzle was built by Tanner Frisby and before also by TwistyPuzzles forum member Sublime. The internal mechanism of the Nightmare Cube is extended so that in some positions one or two axes are locked and thus not all moves are possible, which makes it difficult to solve.
Meanwhile there is also the option to get this puzzle 3D printed.
Pictures of the internals can be found at the Twistypuzzle forum links.
Size: edge length 6cm