According to the Timothy Zahn 2017 novel, “Thrawn.”
Thrawn is perhaps the most quintessential INTJ I have seen in fiction. Many have typed him as such already, and I really cannot think of any contesting type. Even so, I have outlined exactly what makes Thrawn an INTJ according to the new book specifically.
Ni: Thrawn is first and foremost a brilliant strategist. His philosophy when engaging an opponent is to study them as thoroughly as he is able in an attempt to “know” them, accumulating philosophies, stories, and (perhaps most notably) art from the culture in question. From this, Thrawn makes connections regarding this seemingly useless data and forms a strategy that is unique to his opponent and is aware of that opponent’s worldview and perception. When Thrawn is in the process of making these connections, he remains silent until he has gathered enough data internally to make a complete and authoritative statement on what he has decided.
Te: Thrawn often explains what he has determined via Ni to those who need to act on his conclusion. As an officer, he would be at liberty to give a few orders and leave it at that; however, Thrawn tends to efficiently, logically, and thoroughly convey his findings to those around him. When he withholds information, it is for a purpose that is usually revealed later on. To Eli especially, Thrawn is an instructor. His journal acts as another way to externalize his thoughts, and ultimately, to teach.
Fi: When Thrawn experiences emotion, he internalizes it. He channels his experiences into lessons in his journal rather than externally cope. When speaking to others, Thrawn often speaks bluntly, but does not speak emotionally. His deeply internal sense of emotion and being provides him with a strong, individual sense of morality that allows him to hold onto his beliefs even when surrounded by an Empire that does not share his views.
Se: Thrawn’s response to external, sensory action relies heavily on his prior thought regarding how best to proceed. In other words, he often replaces instinct with his primary Ni and avoids the use of Se entirely, save in execution. When he was jumped by fellow cadets at the Imperial Academy, Thrawn defended himself rather poorly. It is one of the only instances in which we see him perform less than stellar. Later in the book, Thrawn matches the owner of a dojo in one-on-one combat, which indicates that he studied his weak area and strengthened it. Being more matured as a personality, Thrawn is not often hampered by his inferior function, but works around it when possible.