The blighted furnaces of Zharr-Naggrund endlessly churn out heavy, black-bladed weapons, each inscribed with dark runes that glow with an evil light.
A hand weapon carried by a model with this special rule has the Magical Attacks special rule and an Armour Piercing characteristic of -1.
Note that this special rule only applies to a single, non-magical hand weapon and does not apply to a model’s mount (should it have one). If the model is using two hand weapons or any other sort of weapon, this special rule ceases to apply.