Hellfury Bolts

When you give a model this Relic, select one bolt weapon (see Codex: Space Marines) that model is equipped with. When the bearer shoots with that weapon, you can choose for it to fire a hellfury bolt. If you do, you can only make one attack with that weapon, but when resolving that attack, if it scores a hit it inflicts 1 mortal wound on the target and the attack sequence ends.