Complex sentence: Glaurung then dies, and his spell of forgetfulness passes from Niënor, and remembering her entire life she throws herself off the nearby cliff into the river Taeglin, and is washed away.
Split into simpler sentences: Glaurung then dies, and his spell of forgetfulness passes from Niënor. Remembering her entire life she throws herself off the nearby cliff into the river Taeglin, and is washed away.