Guna means quality, and this category refers to the predominance of sattva, rajas or tamas. Please note that object, to succeed, prosper, to be successful, to all of these categories can never be applied blindly to a persons life! In case of the gunas of a nakshatra, it is clear that these form only one factor out of many. The guna of rashis might be found to be of greater significance, while those of the grahas are certainly of a greater importance. Furthermore, and most important of all, it is the overall structure of a chart in which the planetary arrangements, associations and dignities all have their say - that indicates the guna of a person as a whole. Needless to say, the guna will be subject to change according to the dashas, antardashas, etc. and transits that the person is experiencing in his development to unity consciousness, in which he anyway will be permanently established in sattva - nitya sattvastho.