Complex sentence: Will is described as having straight black eyebrows, dark hair, a strong, jutting jaw, a muscular build (for his age) and often a passionate ferocity in his eyes into which most characters in the trilogy avoid looking directly.
Split into simpler sentences: Will is described as having straight black eyebrows, dark hair with a strong, jutting jaw. He is quite stocky and has a muscular build (for his age) and dark, fierce eyes into which most characters in the trilogy avoid looking directly.