Armour of Contempt

WHEN: Your opponent's Shooting phase or the
Fight phase, just after an enemy unit has selected
its targets.

TARGET: One ADEPTUS ASTARTES unit from
your army that was selected as the target of one
or more of the attacking unit's attacks.

EFFECT: Until the end of the phase, each time
an attack targets your unit, worsen the Armour
Penetration characteristic of that attack by 1.