Complex sentence: Earlier in life, as seen through flashbacks contained in the second and sixth books, Tom Marvolo Riddle was handsome and tall with pale skin, jet black hair, and dark eyes.
Split into simpler sentences: Earlier in life, as seen through flashbacks contained in the second and sixth books, Tom Marvolo Riddle is described as handsome. As Tom Riddle, he was tall and had pale skin, jet black hair, and dark eyes.