Ender imagines the salamander army as the wolves in the game. what gives ender hope in the midst of these "wolves"?

I believe the answer is: They hope he can be with the other boys and he can get along with him.

(in the story, those children that ender knew has the ability to turn into wolves and attack)

During this part of the scene, He relied with his mental strength that granted him with toughness and endurance.