Sephiroth is a character in the Final Fantasy series and the main antagonist of the video game Final Fantasy VII developed by Square. He is a mutated human, formed from the cells of an alien lifeform and an unwanted fetus. A former soldier of the megacorporation Shinra and the coworker of Zack Fair as well as the superior of main protagonist Cloud Strife, he possesses superhuman physiology as a result of an experiment in which Shinra injected him with cells from the extraterrestrial lifeform Jenova when he was still a fetus. Upon discovering this, Sephiroth becomes consumed by rage and decides to take control of the Planet by harnessing its life force and annihilating all life on it in order to become a god amidst the destruction. Sephiroth's background and role in the story are expanded upon in the Compilation of Final Fantasy VII. Additionally, he appears as a guest character in other video games and media, such as a recurring boss in the Kingdom Hearts series and as a playable character in Super Smash Bros. Ultimate.

Final Fantasy VII is a 1997 role-playing video game developed by Square for the PlayStation console and the seventh main installment in the Final Fantasy series. Square published the game in Japan, and it was released in other regions by Sony Computer Entertainment, becoming the first game in the main series to have a PAL release. The game's story follows Cloud Strife, a mercenary who joins an eco-terrorist organization to stop a world-controlling megacorporation from using the planet's life essence as an energy source. Events send Cloud and his allies in pursuit of Sephiroth, a superhuman who seeks to wound the planet and harness its healing power to be reborn as a god. During their journey, Cloud bonds with his party members, including Aerith Gainsborough, who holds the secret to saving their world.