Mutoid Vermin [Legends]

While an enemy unit (excluding MONSTERS and VEHICLES) is within 6" of this unit, each time a model in that unit makes a melee attack, subtract 1 from the Hit roll.

This ability always takes the form Feel No Pain X+. Each time a model with this ability would lose a wound, roll one D6: on an X+, that wound is not lost. 

If your Army Faction is Heretic Astartes, each time a unit with this ability is selected to shoot or fight, it can make a Dark Pact. If it does, it must first take a Leadership test before any effects of the Dark Pact are resolved; if that test is failed, that unit suffers D3 mortal wounds. Then, select one of the following abilities for that unit’s weapons to gain until the end of the phase: ■ [LETHAL HITS] ■ [SUSTAINED HITS 1]

Each time an attack made with a [LETHAL HITS] weapon results in a critical hit, you can choose for that attack to automatically wound the target.  Designer’s Note:* Choosing to automatically wound the target means that no wound roll is made for that attack. You may decide against this, as it means that attack cannot result in a critical wound* and so cannot trigger other abilities such as [DEVASTATING WOUNDS].