Ender and his siblings, Peter and Valentine are the main characters. The expedition begins with Ender getting his monitor off and later being taken to battle school.
Ender is conflicted because he just wants to live a normal life, however, he is a genius and is needed to save humanity.
Ender is not able to get what he wants because he would be responsible for all of humanity's death if he didn't try to beat the buggers. After Ender unknowingly destroys the buggers and wants to help them after what he did.
Ender does not get exactly what he wants because he can't return to Earth or else a war will start because of him. Instead of going to live in peace on Earth, he goes to a colony on another planet. On that planet, Ender finds a baby queen bugger and wants to find a safe place for it to repopulate it's species.