Mobidus Bolts

When you give a model this Relic, select one bolt weapon (see Codex Space Marines) that the model is equipped with, When that model is chosen to shoot with, you can choose for that weapon to fire a Morbidus bolt. If you do so, you can only make 1 attack with that weapon, but if that attack scores a hit:

• The target suffers 2 mortal wounds and the attack sequence ends
• Until the end of the turn, subtract 1 from Combat Attrition tests taken for that enemy unit.