WordNet records no synonym and no antonym for personality. It is the only member of each of its synsets, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
the complex of all the attributes--behavioral, temperamental, emotional and mental--that characterize a unique individual
“their different reactions reflected their very different personalities”
Synonyms, antonyms and the broader and narrower relations for personality come from Princeton University’s WordNet. Full sources and licences.
a person of considerable prominence
“she is a Hollywood personality”