Who is Ender's brother?

Peter is Ender's older brother. He is ruthless and brilliant but also sadistic. He skins squirrels and threatens Ender's life. At first, the International Fleet considered him to be a candidate they might train to be a commander against the buggers, but they decided that his temperament was too vicious--he would not be able to win the love of his subordinates and work with a team. He was underestimated, however, in that he is willing to do whatever it takes to take control over the world. Peter matures and mellows during the novel, taking on some of the character of his younger sister, Valentine, through her influence. He and Valentine become more like one another by working together on his persona Locke and her persona Demosthenes, who anonymously affect public opinion through their writings. Peter's persona, Locke, expresses a calm and wise influence on the world, which is Peter's strategy for earning the respect that he needs to influence others. At the end of the book, Peter has become Hegemon, a ruler of the world, and he has persuaded the world to adopt Locke's plan for peace instead of constant fighting.