Chapter Relic (IH): The Mindforge Stave

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 attacking with this weapon Piles In and fights at Initiative step 1, unless it is a Monstrous Creature or a Walker.