The Ruby of Morpheus, the Stone of Dreams, is the hardest to explain. It is visibly imbued with the power of the Dream Lord, its very essence, but why is a little vague. Suffice it to say that whoever wields the ruby wields most of the power of Morpheus. With it, the wearer can shape the very fabric of reality. John Dee (David Thewlis) does the same thing and a lot of people die because of it.
Again, this is confusing because it is never said that the Dreamstone has inner strength other than what Morpheus absorbs into himself. Why did he need it? Why couldn’t he just keep that power within himself? It is unclear, but possible, that he needed him as a separate, unique conduit for his most powerful abilities. The sand of dreams creates life and opens doors, but the ruby controls the space in which these things exist. In terms of destructive power, this is a sword against a nuclear bomb. But, apparently, Morpheus does not need all this. what a lot, given what’s been happening since the John Dee incident.