it would have to be either Bean or Locke (Peter Wiggin) from Shadow of the Hegemon and Enders Shadown
Peter:
While Ender is away in battle school to be trained to fight the alien Formics, or "buggers", Peter, at the age of 12, convinced Valentine to use their parents' network identities (and eventually their own) to submit to the world great and influential writings under the names of Locke (Peter) and Demosthenes (Valentine).Demothenes was the rabble rouser who was very anti Russian and quickly became popular in the suspicious minds of those on earth who always suspected the Russians were up to no good. Locke was the calm measured voice who wasn't immediately popular but ended up being more popular of the two due to his decisive arguements and resonable nature (not like me in the least!!)
Peter's role back on earth grew as the war with the Formics ended. When Valentine left with Ender, he was the sole mind behind both Locke and Demosthenes on Earth, and he continued to influence public opinion with the personalities. Eventually he declared that indeed he was behind the writings of these two pen named philosophers. He was subsequently elected Hegemon.
Bean: orphan. was made in an experiment which was to change a gene in him which enables him to continually learn things at an incredible rate, with the payoff being that he will lead an incredibly short life, but will be super smart. he lacks a lot of human emotions and but has been taught how to "feel" by those close to people.