Prescience

Prescience has a warp charge value of 7. If manifested, select a Heretic Astartes model within 18" of the psyker. You can add 1 to all
hit rolls made for that unit until the start of
your next Psychic phase.
By focusing his warp-sight the psyker can guide
the aim of his allies, bringing a swift and merciless death to their foes.