Talk:"Be the real Onmoyoji!"/@comment-1004812-20140529141740/@comment-24279374-20140531143126

Onmyoji were specialists in magic and divination. Their court responsibilities ranged from tasks such as keeping track of the calendar, to mystical duties such as divination and protection of the capital from evil spirits. They could divine auspicious or harmful influences in the earth, and were instrumental in the moving of capitals. It is said that an onmyōji could also summon and control shikigami. (from wikipedia)

I do believe ghost agent is translated from onmyoji, and daemon translated from shikigami.