Bass

Bass, known as Forte (フォルテ Forute) in Japan, is a Robot Master created by Dr. Wily to imitate Mega Man's design, along with Treble, an imitation of Rush's design

History
He was created based on a research conducted on Mega Man with the intention of surpassing his power sometime during or before the events of Mega Man 6, and made his debut in Mega Man 7. Bass is the prominent anti-villian of the original Mega Man series, and his goal is to become the most powerful robot in existence. Although Bass and Mega Man are rivals, at times they team up to take down mutual enemies of the two. Despite being created by Dr. Wily, Bass frequently rebels against his creator, usually for his own purposes. Bass was later succeded by Zero, an advanced creation from Dr. Wily.