Humlae, the character I meant (the guy with blonde hair) was supposed to have been ordained a priest and went to the city to study. However, he instead became a petty criminal, really a grifter, but not a very good one. He needs money, so he tries to sell this necklace/amulet that he was supposed to inherit from his father to a thug (who works for a black market antiquities dealer/smuggler), but while his father shows it to the thug, he doesn't actually sell it. So the thug ends up stealing the head of the local Buddha statue, Ong Bak. His boss takes it, but is not terribly happy.
Ting (Tony Jaa's character) is sent to the city to recover the head, being the village badass. They give him all their money they have (which isn't much) for the journey. So Ting gets to town and looks up Humlae to try to help (Humlae's father still thinks he plans on being a priest, and so is "good"). Humlae rebuffs Ting at first , but when he learns Ting has money, he befriends him in order to steal it. Which he does.
The rest of the movie, albeit with a lot of fights and chases, basically follows Humlae's path. Ting, the character, doesn't really do much but fight.
Major spoiler:
Anyway, at the very last scene, Humlae gives up himself to save Ong Bak from being smashed to pieces. Moments later, a giant Buddha head rolls off the platform and squishes the main bad guy
(In the final scene, which I think was tacked on, we see Humlae alive and riding an elephant, presumably having become a priest. I think he might have died in the original cut, or at least it was left ambiguous)
But the way the camera focuses on the Buddha's smile in the 2nd to last scene, makes me wonder if he didn't engineer the whole thing in the first place. As a way to get Humlae to redeem himself.
The whole redemption bit is not particularly new. Heck, it's in Star Wars. But I thought it was well done in this case and so I enjoyed the story just as much as I did the action.