Everyone likes a good kung fu movie, at least all the cool people do. And there have been some masterpieces over the years, with moving stories (when necessary), and graceful martial displays, or maybe just a lot of guys smacking each other around better than we mortals could ever hope to. That doesn't mean that a martial arts movie can't be shoddy or disappointing, however. And, sadly, that's what Warrior Assassin turns out to be.
Feiyang is the spoiled son of a Chinese nobleman, who studies martial arts with his teacher Old Wei. Feiyang doesn't seem too interested, and Wei regularly bests him. One day, without warning, Feiyang's father has him tied up and thrown in a dungeon. When he finally manages to escape, he finds his father and household slaughtered, and Wei gone. Presuming, incorrectly, that Wei killed them all, he sets off for vengeance.
He discovers his mistake, but after too long an interval to hold the audience's attention, and is shortly captured, conscripted into the army, assigned as a bodyguard to the king, betrayed, conscripted into a different army, etc. etc.
The whole sequence doesn't make a lot of sense, with people switching loyalties or making big decisions with little motivation or reason, and big stretches of time being skipped over without context. It's hard to follow. But that wouldn't be so bad if the fight scenes were glorious and entertaining. Needless to say, there are a few Baa Ram Ewe movies I've seen that barely held together plot wise, but Warrior Assassin doesn't have a Tony Jaa or Jeeja Yanin, or even a Jackie Chan or Jet Li, to inject the magic. The fight choreography is fine, but pedestrian. The battles often go on pointlessly past the time when the viewer cares.
In short, Warrior Assassin doesn't cohere as a film. It's not awful, just unfocused and uninspiring. There are much better martial arts and / or Chinese historical epics out there which would be better investments of your time. As far as this film goes, Rent It.