The Armor of Shadows

When resolving an attack made with a weapon that has an Armour Penetration characteristic of -1 against a model from your army with this Relic, that weapon is treated as having an Armour Penetration characteristic of 0. In addition, when resolving an attack against a model from your army with this Relic, an unmodified hit roll of 1, 2 or 3 always fails.