2 parallels Sephiroths who will play differently with him:
- the one in the Northern Crater who will tell him he's a puppet created 5 years ago; the new modified memories of Tifa as a kid point to that. Why bother making new memories if it's not to use against him in Northern Crater, and get debunked in the Lifestream scene? Those new scenes can be very well used by Cloud "but Tifa, at this moment, I recall you called me?" and Tifa be like "uh what?" and plant more doubt. Cloud will use those memories to try to prove that he's real, but those are modified so they can only further that he's not real.
- the one from chapter 18 who will push him to join him; I am not sure when his best bet is for this though? Northern Crater, the other Sephiroth is there, he won't show up. After, his mind is broken, he's basically useless until the Lifestream scene. I always thought he'd appear as the great bad guy at the very end, after we defeat the Sephiroth from our timeline. Does he need all the events of the OG to go on? Maybe he will try to interfere in some way in the Lifesteram scene. What I can tell is that he doesn't like Tifa, so I'm always wondering - does he need her to help Cloud in the Lifestream, or not?