Each soul has a Calling, which is akin to a vocation. The Souls apparently view their Calling in a dutiful light and/or a fair exchange for the goods each Soul can take without direct compensation to the provider (as Soul economy is devoid of the concept of money). Examples of Callings include Healers (medical professionals), Comforters (psychological therapists), Seekers (who hunt the remaining indigenous sentient inhabitants of a world) and other Callings which are merely human jobs in post-Soul invasion form.
They tend not to keep the name of their host after insertion, but revert to their own names (which are usually translations of names they had on previous worlds). Darren is a notable exception. They may also take a new name matching their current world and may even create one from a concept matching the Soul (such as "Wanderer").
Due to their nature Soul society, though thriving on the debateably unjust destruction of other sentient species, is a very peaceful and ideal one based on equal love and understanding.
The Souls do apparently, however, have a controversial ideology against other sentient species as they are willing to dispose of them and take their place to make their world a "better place" with disregard for the sentience of their hosts (debatably they wouldn't treat another of their own kind in this way).
They tend to preserve most of the positive and neutral elements of the society they replace (experience is an important Soul idea), while refraining from the negative (evil; harmful) components as far as possible. They do however replace the aeronautics and health care components with more efficient versions.