Remorse

Remorse can be spent on a weapon and it will act like a blade venom, lasting for a minute or so. If an entity takes effective damage from that weapon, they will suffer remorse for all of the bad things that they have done.
In most cases, it will do no more than cause a few moments of hesitation as the victim reviews their life and re-evaluates themselves. Normal people have little to feel deeply remorseful for.
Against those things which are deeply evil, remorse does more. Because the evil is so great, the evaluation is greater. The most likely result if they are suddenly inflicted with it is that they will try to leave the current conflict and meditate upon their moral condition.
It is important to note that remorse does not stop them from being evil. They may, after a period of deep thought on the matter, decide that they are quite happy with themselves the way they are and go straight back to performing acts of evil. They may, however, change their position and embark on a programme of change.
This, then, is a grace period in which the target may choose an alternative moral/ethical position to carry on with. They may be encouraged to follow another path by others. Indeed, they are usually quite suggestible in this regard. Remorse will work on anyone, however, the more evil, the more acts of contrition that may be required to justify redemption.
Because of this effect, denizens of the Seventh Plane will seek to avoid anyone who is known to be carrying Remorse. This is not to say that they won't try to destroy the bearer, just that they will be unlikely to do it up close and personal.
The effect of Remorse on undead is somewhat different, although still quite catastrophic. They may enter the grace period of remorse where they consider their evil.
If, as a result of their ruminations, they decide that they have erred and they are contrite, then this means that they experience Hope. Thus, as undead they are destroyed and their spirit is released as if they had just died normally. Those people who are death or life aspected will sense this as a sentient mammalian birth, regardless of the properly deceased's race.
However, if the undead emerge from their meditations committed to their previous path, then they become even more powerful. Such an undead will be able to make use of elemental Despair over and above any other abilities they may already have. If they already had access to elemental Despair, they have more now.