WordNet sense 1 (someone who has exceptional intellectual ability and originality):

brain, mastermind, Einstein, brainiac

WordNet sense 2 (someone who is dazzlingly skilled in any field):

ace, adept, champion, hotshot, maven, sensation, star, superstar, virtuoso, whiz, whizz, wiz, wizard, mavin, adept

WordNet sense 3 (exceptional creative ability):

wizardry

WordNet sense 4 (a natural talent):

flair

WordNet sense 5 (unusual mental ability):

brilliance