How about being able to fix that whole in your soul?
For every point of essence you have lost, you can spend a cumulative 20 karma to regain a single point of essence. For the first point you heal, it costs 20 karam. The second costs an additional 20 karma for a total of 40 karam in addition to the 20 for the first point or 60 total. The third would cost 60 karam and so on.