four-dimensional cube

It's a cube that constantly shrinks and grows in size. It's two cubes linked by the vertices, with ever-shifting sides folding onto each other, over and over. It's four cubes in the exact same position. It's a cube fading to ash then reverting to pristine form repeatedly. It's all of these at once, and none of them at all. It is the only one of its kind. It may have unknown powers; try activating them.