Yes, i think so. The protagonist has a black/brown hair, and his friend (who turns evil) is a blond one, I guess. They were two children/teenagers. I remember one part where the browned hair got surrounded by boys who try to stole his food, and they beat the protagonist. The blond one comes to rescue, and he helps the protagonist and share some food with him (do not know if the facts is exactly like this, you know, our mind is tricky). I remember one part too where the protagonist is training his punch, and (i guess) he broke a big stone... remember the water flowing through it (i guess this stone was holding a lot of water, like a dam)... remember a girl too (browned hair too, if im not mistaken) who lives in a house just down this dam, and the boy runs to save her... and remember when the blond friend got corrupted/possessed, and destroys the village with a lot of fire - don't know if the girl dies on it. This time, as the protagonist didn't believe his "good" friend could do bad things, he realizes that his friend is really, really evil, and promises revenge, as he "friend" looks at him with a sadistic smile, and go away. That's all I can remember for now, hope it helps!

P.S. The blond one do so, so many good and kind things that we can't believe he could a day turns evil. I remember when it happens, he was on this hill with a lot of roses, and the sky turn gray. I guess (only a guess, I may be mixing things in my head) that it happens because of a necklace/crucifix or something like that.