The Sanguinor

While a friendly Adeptus Astartes unit is within 6" of this model, you can re-roll Battle-shock and Leadership tests taken for that unit

(Once per battle, per army) At the end of your opponent's Charge phase (excluding the first battle round), you can select one enemy unit that made a charge move this phase. This unit can make an ingress move and must be set up engaged with that enemy unit.

Unless part of an attached unit, this unit is not visible to enemy models unless they are within 12" of this unit, and it cannot be targeted by [INDIRECT FIRE] weapons unless the attacking model is within 12" of this unit.  If this ability takes the form Lone Operative X", unless part of an attached unit, this unit is not visible to enemy models unless they are within X" of this unit, and it cannot be targeted by [INDIRECT FIRE] weapons unless the attacking model is within X" of this unit.

Each time this unit makes an ingress move (20.04), if every model in this unit has this ability, it can be set up anywhere on the battlefield that is more than 8" horizontally from all enemy units, even if that is within your opponent’s deployment zone.

While every model in a unit has this ability, that unit is a Fights First unit.  See the Resolve Fights First Combats step in the Fight phase (12.04).

If your Army Faction is Adeptus Astartes, at the start of your Command phase, select one unit from your opponent’s army. Until the start of your next Command phase, that enemy unit is your Oath of Moment target. Each time a model with this ability makes an attack that targets your Oath of Moment target: ■ You can reroll the Hit roll ■ If you are using a Codex: Space Marines Detachment and your army does not include one or more units with the Blood Angels, Dark Angels, Deathwatch or Space Wolves keywords, add 1 to the Wound roll as well.

Each time an attack made with a [DEVASTATING WOUNDS] weapon results in a critical wound, the attack sequence for that attack ends and the target unit suffers a number of mortal wounds equal to the D characteristic of that weapon. These are inflicted after resolving any normal damage inflicted by those attacks.  Mortal wounds inflicted by [DEVASTATING WOUNDS] weapons can damage a maximum of one model for each critical wound; any remaining mortal wounds inflicted by that attack are lost.  Example: An attack made with a [DEVASTATING WOUNDS] weapon with a D characteristic of 3 results in a critical wound against an Intercessor Squad, so inflicts 3 mortal wounds. The first 2 mortal wounds are sufficient to destroy 1 Intercessor model, so the remaining mortal wound* is lost.