Ender knew that at this moment he might be able to walk out of the room and end the battle. The way he had escaped from the battleroom after drawing blood. But the battle would only be fought again. Again and again until the will to fight was finished. The only way to end things completely was to hurt Bonzo enough that his fear was stronger than his hate.
Hurt those who hurt you until they can't do it again.
― Orson Scott Card, Ender's Game