So, the original game is very vague and fuzzy, especially at the end. The Remake at least makes a better pass at clarifying wtf is going on. That said, my reading based on my playthrough of both iterations is…
spoiler
Sephiroth was killed by Cowgirl Tifa back in Nibelheim, as revealed in the flashbacks. However, his soul was so polluted by Jenova that he could not return to the Lifestream. Like the Gi, he is cursed to persist in a kind-of ghostly half-life between worlds. He can possess and manipulate living people, but he cannot properly die or pass through the Lifestream and live again.
As part of this half-existence, he can see the alternate versions of himself in different histories. In other iterations of the world, Sephiroth has already claimed the Black Materia and triggered the coming of Meteor. So Sephiroth suspects what is going to happen based on the actions of alternative versions of Avalanche and Shinra his alternate self has already experienced.
Shinra Soldiers also have this capacity, to a limited extent, which is why Cloud can still see a ghostly version of Aerith - the version of her that he’d saved from Sephiroth in an alternate timeline. And, when Cloud is thrown into the Lifestream in Act 3, he has an even more vivid connection to the alternate timelines, allowing him to confront and defeat Sephiroth in his final form.
That’s an alternate reality Sepheroth, who is apparently aware of the alternate realities and has observed some of their outcomes. At least that was my understanding.
Isn’t it both? I vaguely remember Sephiroth already knowing what’s going to happen or him coming from the future or something.
So, the original game is very vague and fuzzy, especially at the end. The Remake at least makes a better pass at clarifying wtf is going on. That said, my reading based on my playthrough of both iterations is…
spoiler
Sephiroth was killed by Cowgirl Tifa back in Nibelheim, as revealed in the flashbacks. However, his soul was so polluted by Jenova that he could not return to the Lifestream. Like the Gi, he is cursed to persist in a kind-of ghostly half-life between worlds. He can possess and manipulate living people, but he cannot properly die or pass through the Lifestream and live again.
As part of this half-existence, he can see the alternate versions of himself in different histories. In other iterations of the world, Sephiroth has already claimed the Black Materia and triggered the coming of Meteor. So Sephiroth suspects what is going to happen based on the actions of alternative versions of Avalanche and Shinra his alternate self has already experienced.
Shinra Soldiers also have this capacity, to a limited extent, which is why Cloud can still see a ghostly version of Aerith - the version of her that he’d saved from Sephiroth in an alternate timeline. And, when Cloud is thrown into the Lifestream in Act 3, he has an even more vivid connection to the alternate timelines, allowing him to confront and defeat Sephiroth in his final form.
That’s an alternate reality Sepheroth, who is apparently aware of the alternate realities and has observed some of their outcomes. At least that was my understanding.