Rakshasa gana, the demonic class, covers nine nakshatras including Krittika, Ashlesha, Magha, Chitra, Vishakha, Jyeshtha, Mula, Dhanishta and Shatabhisha, and denotes a temperament the texts describe as forceful, independent, self-willed, quick to anger and capable of great effort; the association is with tamas, though some authorities place it with a fierce form of rajas.
The name should not be read as a moral verdict. Rakshasa in Sanskrit literature names a class of beings, not a category of wicked people, and the astrological use of the term is a classification of energy and temperament, not of character in the ethical sense; several of the nakshatras in this class are among the most powerful in the system. It is worth being explicit about this because the Ashtakoota system deducts points for a deva and rakshasa pairing, and the label has in practice been used to discourage marriages, which is a considerable weight to place on a category whose name is being misunderstood.