A massive mythical blue dragon with large wings, wings spread, sleeping on a treasure hoard, deep in an underground cavern, its shimmering blue scales reflecting the glow of enchanted gems, the dragon's scales are finely detailed, with sharp ridges along its neck and head, giving it a fearsome appearance and its expression is menacing with sharp, exposed teeth, with ancient runes carved into the walls, epic scale, overall mood is dark and intense, dark fantasy, highly detailed environment,