The Ashen Estus Flask is a dark, weathered flask with a gothic design, featuring intricate engravings of undead motifs and a slightly cracked surface. It has a metallic sheen with a deep blue hue, suggesting its magical properties, and is bound by leather straps for grip. The flask's form is slender and curved, designed to fit comfortably in one hand, with a stopper that emits a faint glow when in use.