The castle of shadows usually lives in the twilit lands.
Its walls grow hardest in the in the deserts of the kingdom of the unsetting sun – shadows are strongest in defiance of light – but it stands out, stark and black against the sun-bleached sands.
In the fields of eternal night it is nigh invisible – a shadow on a sea of ink; black on black.
So it stays in the twilit lands, neither solid nor ethereal, the comfortable half-space of neither-being-nor-not-being, where dreams are half-realised, half-forgotten; the limbo of the freedom and security that comes from having nothing to lose and nothing to take; where the walls are painted with illusions and allusions of things that might-perhaps-have-been.
Perhaps the castle of shadows, where the tenebra-prince sits on the umbral throne, is not a happy place – but that is sometimes the price one pays to live in a half-place. Would he be happier as a peasant in the warm sands of the sunrise empire? Or as king in the inkwell palaces of the under-dark?
These are conjectures and speculations in which the tenebra-prince does not indulge. For he knows who he is, and where he is, and what his life must be.
For his is a life that needs no metaphor.