Cloaked by the Storm

Use this Stratagem in your Psychic phase, after
resolving the effects of a psychic power from the
Tempestas discipline manifested by a Space
Wolves Psyker model from your army.
Until the start of your next Psychic phase, each
time a ranged attack is made against a friendly
Space Wolves unit within 6" of that Psyker,
subtract 1 from that attack’s hit roll.