Corvus Blackstar

Some models have 'Deadly Demise x' listed in their abilities. When such a model is destroyed, roll one D6 before removing it from play (if such a model is a TRANSPORT, roll before any embarked models disembark). On a 6, each unit within 6" of that model suffers a number of mortal wounds denoted by 'x' (if this is a random number, roll separately for each unit within 6").

Some AIRCRAFT models have 'Hover' listed in their abilities. When you are instructed to Declare Battle Formations, before doing anything else, you must first declare which models from your army with this ability will be in Hover mode.

If a model is in Hover mode,  then until the end of the battle, its Move characteristic is changed to 20", it loses the AIRCRAFT keyword and it loses all associated rules for being an AlRCRAFT model. Models in Hover mode do not start the battle in Reserves, but you can choose to place them into Strategic Reserves following the normal rules if you wish.

If every model in a unit has this ability, then each time a ranged attack is made against it, subtract 1 from that attack’s Hit roll.

Refer to the Detachment Rule for more information.

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 Black Templars, Blood Angels, Dark Angels, Deathwatch or Space Wolves keywords, add 1 to the Wound roll as well.