What are Ender's positive characteristics? What are his negative characteristics? How is he the perfect soldier the I.F. wants?

Ender is a great leader, he has good intentions, and he is honorable. He inspires loyalty, respects authority, and when apprised of his situation (meaning he isn't being manipulated), he never acts dishonorably. Ender also possesses an inner strength that assists him in dealing with difficult situations emotions.

Ender can be violent when provoked and ruthless when necessary. He sees winning is the most important part of the game. In the context of the novel, these would not always be considered negative traits. On the other hand, these traits made up a large part of the reasons he was chosen as commander.