While those looking for wall to wall martial action would be better to look elsewhere, this film is best viewed by those familiar with the legends, heroes, and characters stemming from the Three Kingdoms novels and TV series and films like Red Cliff and Resurrection of the Dragon. The plot features appearances from several characters from those stories that would be familiar to readers (similar to say the Avengers-related cameos in several of the recent Marvel heroes films) and there are several enjoyable scenes that delve into explaining details of Yen's character's legend. Similar to many of the recent films and series revolving around the King Arthur/Round Table legends.
For those unfamiliar with the Three Kingdoms characters and stories, I can understand that there would be some confusion with the characters and their relationships with each other. This lack of a more in depth familiarity may diminish some enjoyment as Yen's terrific martial action scenes are sparsely distributed throughout the film. And while it's possible for an uninformed viewer to enjoy the film on it's historical action merits, they may not enjoy this work as much as the more relatable fare found in some of Yen's other recent films. It might be better to think of this film as a historical piece featuring some martial arts action than a martial arts film that takes place in ancient China, if that makes any sense.