Sephiroth (Japanese: セフィロス Sefirosu) is a fictional character in the role-playing video game Final Fantasy VII developed by Square (now Square Enix), where he is the main antagonist. Character designer Tetsuya Nomura conceived and designed Sephiroth as an antagonist to and direct physical opposite of the game's main character, Cloud Strife. The character was portrayed in Japanese by voice actor Toshiyuki Morikawa and in English by both Lance Bass in Kingdom Hearts and George Newbern in all his subsequent appearances.
Sephiroth's role in the game's story, as well as his background, are expanded in the Compilation of Final Fantasy VII. Additionally, he appears as a boss character in the Kingdom Hearts series, and other video games developed by Square.