My version of Abyssals is one based around being driven and hounded. Hunted by the dead and Fate itself. As such, it makes sense that their nature while twisted should be reflected in their flaws of invulnerability.
Compassion - In any scene where the Abyssal refuses to protect one of their intimacies, they pay a 5 mote surcharge on their uses of a perfect defense. This does allow them to defend through offense, rather than just defense, attacking someone threatening their beloved. Should the subject be destroyed, this surcharge changes to 1 willpower per action.
Conviction - Should the Abyssal's Dissonance rise above their highest virtue, they must pursue their Passion in some direct fashion, or find they lose access to their perfect defense.
Temperance - Those who strike at the the Abyssal find that they are given to calm and cold calculation in their attacks. They must take an Aim action to it's full bonus and attack their current target till their DV refreshes twice or the target is dead.
Valor - The Abyssal must attack or approach the target that they last used this Charm against till their DV refreshes once as they seek bloody vengeance. They can not restrain their attack to do anything but kill.