Theorem's Edge

A slender longsword forged from two impossible metals. One half is Aurelith, a holy metal that shines like dawn caught beneath ice. The other is Nullex, an arcane alloy of midnight blue and violet crystal, etched with formulae that shift whenever the blade is observed. A perfectly straight seam runs from pommel to point, dividing radiance from sorcery without allowing either substance to overwhelm the other. The crossguard resembles the spread wings of a luminous insect, while the grip is wrapped in pale leather marked with tiny, moving constellations. When drawn, the sword produces a quiet chord like a distant choir tuning itself.