Spectral knight riding a phantom steed through nebula

A spectral knight, his armor cracked and overgrown with ethereal moss, rides a phantom steed through a swirling nebula. His quest leads him not to a castle, but to a cosmic crossroads where constellations form ancient runes. The style is a blend of dark fantasy concept art and cosmic horror, with influences from artists like John Harris and Wayne Barlowe, emphasizing a sense of vast, unknowable dread.