My theory for the FFVII Remake trilogy: The true chronology is OG FFVII → Compilation → Advent Children → Remake → Rebirth → Part 3. OG/AC really happened and are not being overwritten. After AC, that completed history exists within the Lifestream as part of the Planet’s accumulated memories. Remake is not time travel into OG’s past. Instead, a new branch of existence manifests from the Lifestream using that history as its foundation, which is why Remake initially appears to be recreating FFVII despite chronologically existing downstream of OG/AC. Post-AC Sephiroth is the catalyst. Having maintained his individual consciousness within the Lifestream, he exerts his will upon this new branch. The original history remains encoded within the Lifestream, explaining why the Whispers know how events are “supposed” to happen and attempt to make this new existence conform to OG. Sephiroth isn’t seeing his future. He remembers the history upon which this world is based. Aerith is the counterforce. The commonly referenced “Omni Aerith” is post-AC Aerith, whose consciousness also persists within the Lifestream. She passes memories and knowledge to this branch’s Aerith to help her counter Sephiroth. This explains why Remake Aerith possesses knowledge she shouldn’t have while still being a distinct Aerith experiencing these events herself. But calling Remake a Lifestream branch doesn’t make its world any less real than OG. Everything in FFVII ultimately originates from the Lifestream. The Cosmo Canyon NPC in Rebirth gives us an important clue: spiritual energy may be a manifestation of knowledge and memories, but she questions whether the Lifestream even distinguishes between memories of things that actually happened and “unrealized desires buried deep within our hearts.” If hopes, dreams, memories and unrealized possibilities can all exist within the same spiritual substance from which life and reality emerge, then a world born from those possibilities isn’t necessarily an illusion. It is another manifestation of the same fundamental substance that produced the original world. This is why the different worlds in Rebirth don’t need to be conventional sci-fi timelines. They’re Lifestream shards or branches, manifestations of possibilities stemming from a shared underlying history. Some may be temporary or eventually return to the Planet, but that doesn’t make the people experiencing them imaginary. From their perspective, their lives, choices, suffering and memories are completely real. OG isn’t the “real universe” surrounded by fake copies. OG and the Remake worlds are manifestations of the same Lifestream, with OG serving as the foundational history from which the later branches emerge. So Remake works in either play order. A newcomer experiences Remake as their FFVII and gradually discovers the mystery behind its world. An OG player recognizes an established history being echoed, resisted and changed. In that sense, OG/AC becomes the prequel to Remake, while Remake simultaneously presents itself as a new telling of FFVII. That’s why the developers can describe the original storyline as “enshrined” within Remake’s narrative as “a thing in the world.” Under this theory, that’s almost literal. OG isn’t Remake’s future. It’s Remake’s inherited history. The Lifestream remembers what happened, contains what could have happened, and from both can manifest something new. Remake doesn’t simply recreate OG. It exists because OG already happened. OG → Compilation → AC ↓ that completed history enters/remains within the Lifestream ↓ Sephiroth persists + Aerith persists ↓ new manifestations branch from that remembered history ↓ Remake → Rebirth → Revelation I will include further evidence in comments below.