The Emperor's Auspice

Use this Stratagem in any phase, when an
ADEPTUS CUSTODES unit from your army is
chosen as the target of an attack. Until the end of
the phase, each time an attack is made against that
unit, your opponent cannot re-roll the hit roll,
wound roll, or damage roll for the attack. If that ADEPTUS CUSTODES unit contains 4 or fewer models, this Stratagem costs 1CP; otherwise,
it costs 2CP.