This book features many themes throughout the story. There's loneliness, hope, and betrayal. All featuring Ender Wiggins, the hero of the Formics War. So read, slouch and in your chair and relax. I hope you enjoy the themes showcasing Ender.
Ender has gone through a heart breaking betrayal by his closest friend and only sister, Valentine. To be betrayed by your sister so that she can go onto your pyshcopath brother is the most heart-wrenching thing ender could have experienced. He trusted her and together the rebelled against peter but now she has joined forces with him and now he has no one who looks out for him.
Ender is left all alone. Due to stereotyping many people never want to be around him because "he's going to be the new commander, stear clear." Also his old friends can not see Ender anymore due to the strict rules of the commander who want Ender to be isolated. I bet he feels very miserable and depressed.
Ender has hope that maybe he will get his life back someday and that he will leave Command School. The people there have been nothing but cruel to him isolating him and forcing hime to do things he doesn't wish to do. The oppertunity presents itself to ender and ender tries getting expelled and has high hopes but as a result it backfires on him actually making the commander happy.