Ender's Game Question

Mazer Rackham was the hero of the Second Invasion. He succeeded when he blew up the queen bugger's ship and thus wiped out all of her "worker" buggers. Using relativity, he has survived to the present in order to be Ender's teacher at Command School. He remains extremely quick, physically strong, and very smart. Mazer tells Ender right away that he is Ender's enemy, because the only teacher worth having is one who takes the role of an enemy. Mazer and Ender are the only two people to be able to pick out the queen's ship, it seems, from the videos. Later, Mazer and Graff trick Ender into thinking that the battles against the buggers are just more battle games.