Malleus Argyrum

While Force is in effect, re-roll To Wound and Armour Penetration against models with Daemon rule.

A model that suffers one or more unsaved Wounds from a weapon with this special rule is reduced to Initiative 1 until the end of the following Assault phase.

Any Psyker that has one or more weapons with this special rule knows the Force psychic power in addition to any other powers they know.

Force - Warp Charge 1
Force is a blessing psychic power that targets the Psyker and his unit. All of the targets' weapons that have the Force special rule gain the Instant Death special rule until the start of your next Psychic phase.

A model fighting with this weapon does not receive +1 Attack for fighting with two weapons unless it is armed with two or more Melee weapons with the Specialist Weapon rule.