Sephiroth is the main antagonist of Final Fantasy VII, and one of the major villains of its extended universe. A prototype SOLDIER and the strongest alive, Sephiroth is initially revered for his strength and hailed as a hero, until he learns and misinterprets his origins. Believing himself as the last of the Ancients, Sephiroth enacts a vendetta against mankind, with the ultimate goal of becoming a god and controlling the planet. Sephiroth's goals later include defeating Cloud Strife, who has consistently foiled his plans. To this end, Sephiroth is frequently depicted as Cloud's archnemesis.
Sephiroth is arguably the most popular villain of the Final Fantasy series - his appearance, name, and musical theme are all highly praised among fans and he has appeared in many spin-off titles. He is also consistently voted as one of the top video game villains in polls and lists on video game websites, such as GameSpot and IGN.
In Japan, Sephiroth's voice was provided by seiyuu Shinichiro Miki in Ehrgeiz and Toshiyuki Morikawa in all subsequent appearances including the Kingdom Hearts series. In the English version of Kingdom Hearts, his voice was provided by Lance Bass of *NSYNC fame, a decision that was received negatively by some fans. He is voiced by George Newbern in all subsequent appearances, who has been considerably better received.
Sephiroth's personality is one of cold ruthlessness. Prior to his madness, he was not particularly anti-social, as he has friends in Crisis Core -Final Fantasy VII- and willingly tells Zack and Tifa about Mako and Materia on Mt. Nibel. All the same, his cold exterior and professional attitude turn people away. He is very intelligent, and is respectful to those he deems worthy - he considered Professor Gast a great scientist, but looked down on Professor Hojo and described him as "a walking mass of complexes". Sephiroth is confident to the point of arrogance, but as the strongest SOLDIER alive it could easily be argued he has the right to be. Well-spoken and somewhat graceful, Sephiroth is universally calm, collected, and in control. He can be frustrated and caught off his guard, but this rarely happens.
Following his fall into insanity, Sephiroth retains most of the above personality traits, but becomes murderous and vengeful as well. He also develops something of a messiah complex, proclaiming several times that he is "the chosen one", destined to lead the planet and become a god. His intelligence has increased vastly following his time in the Lifestream, and he has absorbed the knowledge of the Ancients there. At one point, Sephiroth even says he is greater than the Ancients. He has become highly cruel and delights in mentally torturing Cloud, and in Advent Children, in one of his iconic lines, asks Cloud what he cherishes so he may simply take it from him. Sephiroth is also fiercely devoted to Jenova and her cause, even though her body serves as little more than his avatar.
Sephiroth's early designs were done by Yoshitaka Amano and later refined by Tetsuya Nomura. Sephiroth, in all his appearances, wears a long black coat with silver pauldrons, black boots, and black clothing underneath. The top of his clothing underneath his uniform is split to reveal his chest, covered by crossing leather straps. His hair is long and silver, a sharp contrast to Cloud Strife's blond spikes, with his bangs parted to either side of his face. Beyond his clothing and hair, Sephiroth is known for his green cat-like eyes and the Masamune, his seven-foot long katana that he is rarely seen without. Sephiroth's typical battle stance with the sword is to hold it over his left shoulder, and he usually wields the Masamune two-handed, presumably to increase the force of his strikes as he is capable of using it with one hand. In later appearances he has a single black wing emerging from his right shoulder.
In the "Compilation of Final Fantasy VII", Sephiroth's uniform basically remains the same as in Final Fantasy VII, but now his coat has several buckles instead of just one and the traditional "SOLDIER" symbol in his belt is replaced by the new one, which was redesigned for the Compilation. In Advent Children, Sephiroth's hair was animated by hand to make sure it looked as real as possible, and he was given an otherworldly appearance with, as co-director Takeshi Nozue stated, "an attractive nose and thin lips. It's a face you'd never see in real life". In the Kingdom Hearts series, Sephiroth retains his core design of silver hair and a black coat, but his clothing is now given red linings, his coat has changed shape slightly, and he bears his black wing over his right shoulder. In Dissidia, Sephiroth's design is similar to his Final Fantasy VII design, but his pauldrons are changed to resemble Amano's artwork and his coat is closed by a belt as in Nomura's design