Ultimecia is the main antagonist of the game Final Fantasy VIII. She drives much of the story, albeit from behind the scenes. Throughout much of the game, she merely possesses other sorceresses in order to compress time and return to her own body and rule the world.
Ultimecia first came to be by possessing Edea Kramer. Sorceress Edea then became an aide to President Deling of Galbadia, and after killing him, came into power. She used this to her advantage, and after capturing Squall and other SeeD members, she tortured him with Galbadian prisons to find out the true purpose of SeeD.
She continues to circle the globe, seeking out all SeeD members, and is eventually taken on by all of Balamb Garden, which is full of SeeDs. Squall and the group take her down, only to discover that it wasn't Edea they needed to worry about, but rather the soul of another, more powerful sorceress by the name of Ultimecia. Ultimecia possesses Rinoa, who tells Seifer to go and help release Lunatic Pandora.
She then puts Rinoa into a comatose state, and when the time is right, she uses Rinoa to release the notorious sorceress Adel. This, along with the Lunatic Pandora and Moon in the sky, results in the Lunar Cry, sending hundreds of thousands of creatures onto their world.
It is eventually learned that Ultimecia is using a machine from the future to go back in time to possess other sorceresses, all in an effort to get "Time Compression", a melding of all eras of time into one. Taking advantage of this, Squall and the gang slip into Ultimecia's time, and challenge and defeat her.
Ultimecia's final battle is divided into 3 stages:
- The first stage, she is sitting on her throne, hardly giving a care about your attack. You start with a random party, and whenever she kills a character, they get replaced. Eventually you'll have the party you want.
- Stage 2 she pulls out Squall's beloved friend Griever as a GF, and you must battle him. Upon his "defeat", it's a combination battle with Ultimecia and Griever.
- Stage 3 comes and it's the final form. Ultimecia's last form, and after so much damage, the lower half of body is revealed. From there she (and you) can use the powerful spell Apocalypse. Defeating this form results in the end of the game.