The only way to beat the giant Beta is via direct attack to the brain, forcing Ogre into a very perilous situation. Auctioneer risks his life to locate the brain, and Ogre uses Number 11 to take it out and defeat Beta.

He reunites with the Squad and celebrates, but his joy would be short-lived.
Your desire to protect is proof 
of your humanity.
رغبتك في الحماية هي برهانٌ على بشريّتك
Dein Wunsch, andere zu beschützen,
zeugt davon, dass du noch ein Mensch bist.
El hecho de que desees proteger a otros
El hecho de que desees proteger a otros
Ce désir de protéger autrui
qui persiste en toi
Quel tuo sentimento 
di voler proteggere qualcuno
Seu desejo de proteger alguém
é a prova da sua humanidade.
Твоё стремление защищать —
доказательство твоей человечности.