What does Charis mean?
From Greek 'charis' (χάρις) meaning grace, kindness, or charm. In Greek myth the Charites (Graces) were goddesses of grace and beauty; the root also underlies the word charisma.
What does Callista mean?
From Greek kallistos/kallistē 'most beautiful', the superlative of kalos, from kallos 'beauty'. Kalliste was a title of the goddess Artemis; the mythological nymph Kallisto bears the same root.