Ender’s Game Saga, Orson Scott Card
Ni: Bean, like Ender, is a strategist. When Ender sets him up to be hated by the other boys, Bean sees through the ploy just as easily as Ender did when the same thing was done to him. Bean thinks very quickly and deeply. He has an original mind that comes invaluable both in Battle School and in the Bugger War (and later, as the Hegemon’s shadow). Bean is one of the few people that Ender trusts enough to confide in.
Te: Bean is ambitious and craves for leadership as a boy, coming to Ender early on with demands to be made a Toon leader. He is not intimidated by anyone who is older than him, and has little trouble asserting his opinions. He’s blunt and often defiant of authority. Large-scale leadership doesn’t come quite as naturally to Bean as to Ender, but in a small-group, Bean takes control quite easily. Bean is a back-talker with a big ego.
Fi: Bean rarely discusses his feelings, or even really, lets them show. Bean remains relatively unaffected emotionally by personal criticism and alienation. He is mature enough to recognize where his faults are and to take criticism as cause for improvement.
Se: Bean doesn’t always answer all of Ender’s questions with words, but often demonstrates his ability to understand Ender’s instructions and figure things out by simply doing it. Bean is good at reacting quickly to situations, better even, than Ender.
I haven’t gotten around to reading Ender’s Shadow yet, so Bean’s typing is still subject to any changes I might make when I do read it and get new insights into his character.