"Peter"

Those two unknown people who were having a conversation in the last chapter were having a conversation again in the beginning of this chapter. That time, they're showing approval of Ender's actions against Stilson. Ender didn't care about his monitor being taken away, even though his sister Valentine tried to comfort him. Peter suggested to play "buggers and astranauts", a game along the lines of "cops and robbers". While playing, Peter hurts Ender, and Ender then wonders what it's like to be a bugger. Later, Peter threatened Ender, saying he could easily kill him, and Valentine talks him out of it, by saying he can't get into politics if people knew he did something like that. Their parents come home, and Ender knows how awkward he makes them feel, being a Third. Ender was laying in his bed, and he heard his brother come in and he became afraid. His brother ended up apologizing to him, and said he loved him.

While I was reading, the way Peter was manipulative and dangerous was shown, which explains why Ender doesn't want to be like him. Peter's apology at the end shows that there is some good in Peter, although he is shown to be very mean.