Complex sentence: The rise of the movement in the early 2000s is attributed to the saturation of nu-metal in that period and the nu-metal band Korn who are considered one of the bands which initiated the NWOAHM.
Split into simpler sentences: The rise of the movement in the early 2000s is attributed to the saturation of nu-metal in that period. The nu-metal band Korn is also considered one of the bands which initiated the NWOAHM.