Prince Arren, true name, Lebannen, is the primary protagonist of Tales from Earthsea. He killed/severely injured his father (the sword is forged from magic and the blade can only be drawn from its case by certain people, and I doubt the casing of the sword can kill someone, however, in the movie Arren claims he had killed his father) at the start of the film and took his father's sword. After fleeing his father's castle he meets Sparrowhawk, and he stays with him throughout most of the film. He then meets Therru when he saves her from being captured by slavetraders. Arren throughout the film acts strangely, and in the end the viewers learn that Arren was being semi-controlled by Cobb and also that "...darkness/fear had stolen his body..." and the ghost following him is actually his light (in the film a person has "darkness" and "light"). In the end the light and darkness reunites and makes Arren, Arren again.
Arren has brown hair and dark eyes. He wears a old blue shirt (sometimes with a purple robe with gold edges over the blue shirt, and other times he wears a brown cape over his shirt).