Guild Help File
Any being capable of learning will naturally hone their skills as they experience that which lies on their path through destiny.
More complicated beings, Angels, are beyond that simple rule. They may focus their attention towards a certain goal, in an effort to grow strong in a specific principle as well as overall. There are a great variety of these principles that affect combat prowess, and are further more divided by their corresponding Guardian Spirit.
An Angel may only become more disciplined with a spirit it he invoking. To check your current disciplines use the 'discipline command:discipline' command.