Sima Yi

The Wei strategist, Sima Yi was studying, when he heard that Wei was looking for a stratigist. Sima, who knew he could use his talents to rule the land one day readily accepted.

Dynasty Warriors 4
Defeat Ma Chao and Wei Yan
 * Ultimate Weapon: Dark Feather
 * Power: 50
 * How to get it: Battle of Wu Zhang Plains

In Dynasty Warriors 6, his storyline revolves around him using Cao Cao's ambition as a means of gaining control of the land by any means neccesary. In his final cutscene, he is shown slaying Cao Cao, and ascending the throne.