This artwork◊ of the main cast shows subtle hints of their fates and roles in Rebirth. The characters standing on solid rock end up surviving the events of the story while those stepping on dirt have died at some point. Notably enough, Barret is standing on both dirt and rock, symbolizing both his death and revival in Remake. Also notable is that Aerith is the only character who's seemingly walking forward instead of remaining stationary like the rest of the party, as if to say she's about to leave everyone else behind and Ascend to a Higher Plane of Existence. Meanwhile, Cid and Vincent are portrayed on each side waiting in the wings to indicate their Demoted to Extra status.
While the nurturing Cetra's hostility towards the Gi might seem like an Out-of-Character Moment for them, one has to consider that they almost faced utter annihilation from an Eldritch Abomination that originated outside of their home world. As such, they wouldn't be exactly welcoming of more extraterrestrials including those who might not wish them harm.
The game effectively canonizes the party being Made of Iron when we see what happens with Barret and Dyne, both of whom take bullets head-on in story cutscenes during their arc. Yes, it cripples both of them and kills Dyne in the end, but the party has potions and healing magic on-hand that can mend their own wounds. While a gun may still be highly lethal in the right circumstances, it means strong and hardy individuals in-universe can outright shoulder their way through live gunfire in the right circumstances, and that's before counting the resident Super-Soldier and the Materia capabilities.
Despite the Updated Re-release of Crisis Core to help tie in with Rebirth, the Nibelheim flashback notably omits extended elements of that game's portion with Nibelheim, while creating some of its own elements from whole cloth. This effectively explains a lot of why Cloud is an Unreliable Narrator: while he did gain some of Zack's memories thanks to Jenova cells and blatantly self-inserts over top of him, he both overly glorifies the past parts where "he" did cool things, and yet was completely unaware of events like Genesis being involved. There's even a scene cut right at this case that cleverly omits that specific scene. Then there's his injured state through the back half of the flashback, which is likely what really happened since Zack found the trooper Cloud down on the ground in Crisis Core already, having been there to witness Sephiroth finally snap and failed to stop him first.
Why did none of the militiamen in Nibelheim attempt to fire upon Sephiroth despite having him at gunpoint? He's a One-Man Army that's a legendary war hero every single person in the town knew about, that cleared out the monsters probably singlehandedly as far as they knew, even with another First-Class accompanying him. Some part of it might be reverence, but the likelihood is that they all knew they were screwed the instant they approached, and were so terrified out of their minds that their trigger fingers froze up since anyone attempting to shoot was likely the next target to die.
The revelation that the Black Whispers of Fate are controlled by Sephiroth in this game re-contextualizes the trio fight with the Whisper Harbinger in Remake; knowing that they were based off of Kadaj, Yazoo, and Loz, they're effectively a fight of Sephiroth's influence over the planet in his attempts to test and alter fate, intentionally inserting his concept of remnants into the Whispers' "pool" so to speak so he could create a suitable trial for Cloud. If those Whispers were under his control the entire time, it also means he played the cast like a fiddle, intentionally making them think there was a bad future of fate to subvert and letting the Whispers take the blame so he can set up his Take Over the World plot on a far grander scale while simultaneously using them to course-correct the heroes to his desires.
Part of the World Intel for the Gongaga Region mentions how the denizens there are descendants of the Cetra that had decided to settle down. Genetic deviation and changes over time since the Cetra's fall could provide an explanation as to why Zack wasn't as affected by Sephiroth's cells, probably being one of the very rare few people with higher resistance/possible immunity to Jenova's cells. When factoring in his being an Incorruptible Pure PurenessDeterminator, it combines both nature and nurture, something which could explain Hojo's disappointment at Zack due to the professor's predisposition towards focusing on the physical "nature" of his subjects.
Every playable member of the party starts the Final Boss with their Limit Break on the ready, fully enraged at Sephiroth over Aerith's death... except Cloud, who for whatever reason still thinks she's alive, with the jury out on whether it's timeline hijinks or his hallucination. The result is that he's notably upset for the attempt, but completely lacking his emotional anguish and anger. This is even implied by Sephiroth, who seems disappointed that Cloud's hatred for him is rather subdued compared to what he wanted out of him.
This is further demonstrated by Jenova Lifeclinger's Mourning Wail not affecting Cloud because he's the only one who isn't in mourning unlike the other party members.
Sephiroth is at his strongest when Cloud is at his mentally weakest, always seizing power over him or overcoming him, and it's when Cloud manages to solidify his mind that Sephiroth loses. Either Aerith reinforcing his mind instead of letting it fall to despair, or Cloud refusing to acknowledge Aerith had died, has kept him stable enough to actually drive off and temporarily defeat Sephiroth here. In a way, if he is cracking up, Cloud's insanity is ironically stronger than Sephiroth's manipulation, and if we take the positive example of Aerith's aid, she's working damn hard to undermine Cloud's greatest weakness.
One going all the way back to Remake (and in Crisis Core after meeting Zack), Aerith had always shown a particular interest and fear of the sky, especially at the end of the game when she finally leaves Midgar. In the context of Remake, it's assumed that she's simply not used to seeing an open sky unimpeded by Midgar's plates — "I miss it... the steel sky." However, with the added context of Rebirth, it comes to light that she's concerned about the giant dimensional rift in the sky that only she can see — "This sky... I don't like it."
Red XIII being able to sense Aerith at the end should also be a reminder that Cloud wasn't the only one Hojo had experimented on. As shown in Red's trial at the Temple, he had been captured by Shinra troopers to be one of Hojo's experiments, so there's also a possibility that whatever Hojo did may have combined with the physiology unique to Red's species that might have allowed them to have some sensitivity to the planet yet not to the Cetra's level.
Vincent's boss fight, Galian Beast, is weak to being debuffed. Most bosses are immune to this - but party members aren't, foreshadowing Vincent joining the team.
The boss right before Vincent, Forgotten Specimen (Lost Number in the original) has an analysis text explaining it was a failed attempt at creating a being that could shapeshift. It was likely a failed prototype version of the experiments Hojo carried out on Vincent.
The new lore about the existence of a Junon Republic and how its capital was a floating city gives new context to the Sister Ray. Either the cannon was designed to take out large seaborn targets (such as the floating city) or it was built in case Shinra ever had to face something similar again.
During the Combat Trial, Sephiroth has the Reraise materia, and considering that using the Combination Attack gives him unlimited magic use, casting it on himself and Cloud is advised in the tougher battles. Because of course Sephiroth giving himself and Cloud the power to defy death is right up his alley, and Cloud can be right with him in doing so.
During the ending credits, it'll play segments of every cutscene seen throughout the game. However, there's three sections where there are blanks - right when Cloud picks up Aerith and tells her to "wake up" after defeating Sephiroth, where the group are at the lake where maybe!Aerith appears to Cloud, and the section where the others are waiting for Cid to finish repairing the Tiny Bronco as well Cloud equipping the Black Materia, as noticed by user SubTXT on Twitter. This might be one example showing how much of an Unreliable Narrator Cloud has become, questioning whether the Aerith seen from his perspective is still the same one. However, there's still the question for the final end credit cutscene being that of maybe!Aerith seeing off the Tiny Bronco flying away.
At the start of the game, the Buster Sword has more than the two visible materia slots. It's the game literally giving an explanation as to how Cloud is able to attach the Black Materia to his Buster Sword unbeknownst to the rest of the party - it's in one of the slots that isn't visible to the naked eye.
The Sephiroth Clones of the original game were already creepy and tragic enough, but then this game goes the extra mile to showcase the Awful Truth: anyone with Jenova cell treatments, from the Nibelheim survivors to even ex-SOLDIER, can technically be drawn to the Reunion. So long as Sephiroth can worm his way into your very soul, you can be manipulated, to the point that Broden's life was effectively over the moment he was to be used as a pawn for warning Cloud and then left to rapidly degrade into just another Sephiroth Clone in robes. Cloud just happens to be the primary target on Sephiroth's radar because he knows from personal experience that Cloud's his best pawn and his number one threat.
Considering the interservice rivalry between the various units of Shinra's Public Security Forces, especially between units from different cities, the Junon garrison refusing to assist Midgar's 7th Infantry in putting down the escaped experimental fiend, Hell Rider II, can be seen as an attempted Unfriendly Fire by proxy. Let's suppose Junon's units found out that Cloud was the parade captain that got Midgar's 7th Infantry a presidential commendation. Cloud is a rogue SOLDIER, currently working with Avalanche. With the grudge from the parade and this new blackmail info, Junon's troops possibly found a way to get rid of a rival unit: leak intel to the Shinra Resistance Committee, allow the extremists in the Resistance to let Hell Rider II loose from the underwater laboratory, and force Midgar's 7th Infantry to fight the fiend alone without resupply or reinforcements. The troopers who were containing the fiend in question were down to assault rifles and shotguns, weapons that are great against human opponents, but utterly useless against bioweapons.
In Costa del Sol, Hojo remarks to his aides and Tifa that they could help him birth or create a new hero. While distressing on its own, the fact that he is shown to have an interest in the mutated men in black's genetics and his wordings has implications that his process to do so literally is to put them in a tank and expect them to mate. Worse yet, Zack's Tifa is implied to still be alive and has no one to keep her from Hojo's clutches. At least that Hojo is never seen finding out about the mutations.
A scene early in the Gold Saucer has Barret balk at the Ghost Square attractions, using ghosts and special effects all over the place that's powered by Mako energy. One thing the original game didn't really figure on all that much was how only Junon and Midgar emphasized technology, alongside what was built on top of Corel, but this story emphasizes how Shinra put their grubby mits into everyone's pie, so every notable location that isn't an Avalanche-style resistance against them is taken over and decked out with semi-modern conveniences and technology — meaning Shinra functionally made most of humanity horrifically complicit in burning out the planet's own energy and the very souls of their predecessors just to make more profit and keep people complacent. And that culminates in even the fun-time effects and sheer energy of the cheery, iconic Gold Saucer of all things rubbing it in your face of how utterly ignorant people are to all of this while Shinra encourage it for Bread and Circuses. Barret has every single reason to be pissed as hell that this was built on top of his Doomed Hometown, all because he got suckered by their sweet promises like everybody else.
During the party's time in Gongaga, we learn from Barret that the ingredients Jessie mentioned for her pizza recipe are primarily used for love potions. While meant to come across as humorous, some players may find the potential implications behind it disturbing especially considering how thirsty Jessie had been for Cloud at the time.
One unfortunate Shinra trooper messes with the gravity the wrong way in the Temple of the Ancients and is sent flying into the emptiness surrounding the space. The characters treat it as a Black Comedy moment, but that man's either trapped in a looping fall around the temple until he dies of natural causes, or he just got flung off to god knows where to die in a nasty impact with either some part of the temple, or even outright be reabsorbed by the Lifestream forcibly.
One possible reason for why the Temple of the Ancients didn't put Cloud through his own trial like it did to the others is because of Sephiroth's gradual mental influence on him, such as the few times he's mimicked Sephiroth's battle stances and more callous attitude. Another possible reason is that his own modified memories wouldn't work the same way it would've like the others, which may cause him to mentally break more if the Temple showed him the actual truth of Nibelhiem.
The fact that Sephiroth shows up in the Church vision of the long-haired Chihuahua Stamp timeline Aerith shows that he is well aware that besides Cloud, she's the primary obstacle to his goals. And it doesn't matter what she does, how she aids herself across timelines or how she attempts to hide, he will absolutely murder her every single opportunity he gets because she dares to resist his plans. So long as Sephiroth's evil exists, he will kill her, again, and again, and again, effectively creating a warped meta perspective that she must die as fate desires, because Sephiroth refuses to let any threat to his plans slip through his fingers. It also explains why he doesn't immediately kill her in the main timeline as she stands no chance against him with her White Materia depowered by the Black Whispers.
The ending of Aerith seemingly being unable to be sensed by anyone but Cloud (and maybe Red XIII) is a slightly less tragic reminder that this is functionally her fate in the original timeline: keeping her cognizance and remaining an active force in the Lifestream to help her friends and the Planet at large, but unable to do anything in the living realm for them most part, interact with anyone, or really be with them anymore short of visions and loose influences. She sacrificed her life for the sake of everyone and lost all physicality, and as the martyr of the world, was stuck just having to hope and feel good about the decisions she made while seeing Sephiroth and the consequences of his existence try to tear everything apart repeatedly. Now she's seemingly done it all over again — and Cloud, who she hoped wouldn't grow too attached to her, can't let her go.
Sephiroth seemingly knows how fate should go, how he should be losing normally and takes extra measures such as weakening the White Materia of this timeline to try to make himself win more readily. And yet despite all of this, and getting his hands on the Black Materia early, with presumably even the casting of Meteor having already occurred... he gives it to Cloud, while seemingly imparting information for the party to head directly to the Northern Crater instead of any longer routes around. Sephiroth was disappointed in Cloud managing to overcome him here, but he still actively works to send the young man over the Despair Event Horizon, and is still exerting some control over him. Considering he wants to make a very direct pawn of Cloud, it's very possible that a much worse fate is in store than simply abandoning Cloud to be washed up in the Lifestream again.
◊ of the main cast shows subtle hints of their fates and roles in Rebirth. The characters standing on solid rock end up surviving the events of the story while those stepping on dirt have died at some point. Notably enough, Barret is standing on both dirt and rock, symbolizing both his death and revival in Remake. Also notable is that Aerith is the only character who's seemingly walking forward instead of remaining stationary like the rest of the party, as if to say she's about to leave everyone else behind and Ascend to a Higher Plane of Existence. Meanwhile, Cid and Vincent are portrayed on each side waiting in the wings to indicate their Demoted to Extra status.
