Purity of faith

Use this Stratagem in your opponent's Psychic
phase, after a Psychic test is passed for an
enemy PSYKER unit and after any Deny the
Witch attempt is made (if any). If that enemy
PSYKER unit is within 24" of any ADEPTA
SORORITAS units from your army, roll one
D6: on a 4+, that psychic power is denied.