I'm thinking about First SOLDIER.
I still think I'm right about the battle royale being a Synaptic Net Dive (particularly since the event in Ever Crisis where we literally faced down the system that was used to train that first round of would-be SOLDIERs in the battle royale), but the iteration of First SOLDIER in Ever Crisis isn't. Not exactly, anyway. It seems like it's whatever the energetic equivalent of the SND would be for Sephiroth, whatever you would call the way that he (and Lucrecia) can pull memories out of people's heads and put them on display, run through them and relive the experience tangibly, beat for beat—only in Ever Crisis, it's Sephiroth doing it to himself.
Sephiroth gave up his memories in Meteorfall, using his only surviving Clone as an anchor to keep his consciousness from being burned away forever—this is why the Remnants don't actually know him, because they're made from what the Lifestream remembered of him, not from his own concept of himself. He doesn't have a concept of himself anymore, he needs someone or something else to pull him back together.
Jenova "remembers," such as she can, because they were temporarily fused into one being prior to Meteorfall. This is why Kadaj's assimilation of the last piece of Jenova at the climax of Advent Children opened the way for Sephiroth to come back up out of the Lifestream, albeit in an obviously incomplete state.
Cloud also remembers, and he's special: as the only surviving Sephiroth Clone, as the man who struck him down both in Nibelheim and in the Northern Crater, as someone who actually met him prior to everything falling apart, Cloud's memories contain both the most accessible and the most complete version of Sephiroth that can currently be found.
But it's still someone else's memory, because Sephiroth doesn't remember himself.
The Sephiroth at the Edge of Creation at the end of Remake comes from some point well beyond the end of the series, postcanon by some incomprehensible degree. And he's...different. That Sephiroth uses his old personal pronoun, that Sephiroth is almost soft with Cloud—and that's the same Sephiroth as we see at the end of the opening arc of First SOLDIER, because the corresponding cutscene appears to take place just before Cloud arrives at the end of Remake.
That Sephiroth is out there at the Edge of Creation thinking about his childhood, thinking about Rhadore, thinking about Wutai, thinking about who he is and what he's done.
And he remembers. Somehow, in spite of everything, that Sephiroth remembers. He knows what happened to him, what he went through, what he did. He knows himself. And Sephiroth is not some horrifying amalgam of a extraterrestrial pathogen and the incandescent rage of a man created only to be used, he's not an incomplete echo of a memory of a hero long dead; and the Sephiroth at the Edge of Creation knows where he came from, how he got here, and everything that happened along the way.
And he's playing it back to himself.
What's he looking for? What's he hoping to see? Why did he start there, on his first field mission, where he learned the only thing he really had to prove was that he's capable of compassion? Where he learned that it's not black and white, and that death can also be mercy?
Why did he move forward to the night that he ran himself ragged saving lives in an attempt to never have to show that kind of mercy again?
That Sephiroth remembers, and he's choosing to remember this.
And I think...that might make him a Sephiroth that can be saved.
