A colossal ancient obsidian pyramid emerges from crystalline underground cavern at twilight, massive volcanic glass structure with glowing celestial runes piercing deep indigo and ethereal violet darkness. Volumetric prismatic rays illuminate sacred hieroglyphics, ethereal priests chanting around floating luminous orbs. Deep obsidian, mystic violet and crystal cyan palette, epic cinematic low angle shot, divine mystery meets subterranean architecture, 8K digital art