Sephiroth is the main villain of Final Fantasy VII. He was created by Tetsuya Nomura. He was soldier in the Shinra Company, but he became a monster. This story is in Final Fantasy VII: Crisis Core. His goals are to destroy earth with a giant meteor, with the help of the Black Materia and become a god, possessed by JENOVA's genes.
He is known to have a very long sword called Masamune, that he uses to fight, and happen to have a raven wing on his back. His main opponent is Cloud, and gets beaten by him both in Final Fantasy VII and Final Fantasy VII: Advent Children. He also appears in other games such as Kingdom Hearts, Final Fantasy Dissidia and Ehrgeiz. His theme song is called One Winged Angel, and was composed by Nobuo Uematsu.[1]