Yang Wen-li is an unmatched military genius who singlehandedly conquered all of China and could have, if he wished, conquered the world. He provokes fanatical loyalty in all of China and a guarded fear from the rest of the world. The character is almost certainly directly from the series Legend of the Galactic Heroes , where he is described as simply invincible: if Yang is on the other side, you will lose. He is also perpetually lazy and takes the role of a UN Representative while not being chewed out by Hikari Horaki for shirking his responsibilities as the class's history teacher.
Shinji Ikari and Yang Wen-li see in each other a kindred soul. Yang recognizes the worth of the young boy and once offered him command of the armies of China, effectively offering him the ability to conquer the world, which Shinji emphatically refused. As Shinji gathers more power, influence, and even outright worship, often inadvertently or despite himself, the two continue regarding each other with a guarded awe in the realization that they could each conquer the world but have no intention to.
Yang is said to be bad at real-time strategy games such as Age of Empires because they are not difficult or wide-reaching enough, though he is apparently very good at Civilization.