As a result, among warriors of same level, those who owned a Martial Spirit tended to be stronger, and achieved greater results. They did half the work with double the results.
There was a higher probability where one inherited the Martial Spirit.
In general, if one of the parents possessed a spirit, there was a high possibility that their kid would inherit the same spirit. If both of the parents had a spirit, their child would have an even greater chance to inherit one of their spirits, either from the father or the mother.