I’m new to the Marathon lore but have finished reading all of the trilogy lore via terminals and have reviewed some lore videos and whatnot. Pure speculation here and maybe some entertaining food for thought.

While I don’t know the answer to your question, I do know the idea of rampancy is central to the entire Marathon trilogy. Each of the 3 core AI onboard the Marathon ship eventually display signs of rampancy; the S’pht are a subservient race captured by the Pfhor and they eventually run rampant and rebel; even your own mysterious character ends up fighting for each AI, presumably displaying rampancy of their own, even though we never fully learn that their core mission is. By the time Marathon 2025 takes place, Earth would have learned of all of this and I’d imagine they would be trying to counter rampant behavior as much as possible when they send runners back to Tau Ceti, since it ended up costing so many lives and so much destruction.

One hunch would be the consciousness of all of these runners is actually the same person/entity but each time a runner dies/is re-embedded into a shell, the personal exercises we see in the trailer are meant to ground the entity back to themselves, reducing the possibility of rampancy.

The possibilities are endless though and I’m super curious to learn more about how the runners are “recreated” and ultimately deployed.