Let's break down the Kingdom Hearts Missing-Link leak
Let's get a few disclaimers and asterisks out of the way at the top. Obviously, this is leaked content that some are even calling fake. I'm not sure about that, but it's certainly offering a lot of interesting information about the game.
Spoilers for literally anything and everything Kingdom Hearts from the Age of Fairy Tales to the events leading up to Kingdom Hearts 4. This shouldn't be impenetrable, but if you've got questions about any particular subject, a search of specific terms on the Kingdom Hearts Wiki should be sufficient. I'm not going to spend time unfurling every detail, or else I'd still be writing this when Kingdom Hearts 4 released.
(This game series isn't that complicated, just dense. I'll die on that hill.)
A leaked video
First off, there is a lot of conversation about the nature of this video and various screenshots that accompanied it. I'm going to stick to the video itself for now.
It appears that this could be the opening cinematic for the mobile game Kingdom Hearts Missing-Link. Although, beta testers say that no such video existed when they tested early versions. That doesn't mean this isn't real, though it could have been excluded or unfinished at that time.
I do think the quality of the cutscene is in line with Kingdom Hearts media. I'm also tempted to say that this might actually be a leaked opening to a short-film by the same name that might be released before Kingdom Hearts 4 to explain the events of this game no one will ever get to play.
There is precedent: Kingdom Hearts 2.8 contained Back Cover, a short film that tells a little of the story about the Foreteller's struggle, but does little to actually address the surrounding conflict and events leading up to the Keyblade War. For that, you'll have to watch hours of chibi animated cutscenes from a mobile game that's no longer available to play.
(I have, and it's quite a good story. I do wish they'd make it available in some aspect, even in novella form.)
Where Missing-Link falls on the timeline
Anyway, the game was meant to bridge the gap left between Union Cross and Dark Road. Union Cross is the story of you, the Player, working with Keyblade Wielders to collect light from Datascapes in the events leading up to the Keyblade War. It takes place in the Age of Fairy Tales before the world is broken apart by darkness.
Union Cross ends with the destruction of the world by darkness and the recreation of the universe using the light of the hearts of children (the state of things at the beginning of Kingdom Hearts 1).
Dark Road begins at the end of the Keyblade Wielder era, where students of Scala ad Caelum attempt to combat darkness generations after the end of the Keyblade War (how long? It's unspecified, but anywhere between 100 and 1,000 years later).
It follows the story of young Xehanort and Eraqus who have to find out what happened to their upperclassman in the events that lead up to Birth by Sleep.
That gap in the middle, during the era of the Keyblade Wielder society living at Scala ad Caelum, would have been covered by the game Missing-Link. It was going to be another mobile game, though with more modern graphics, but it was canceled.
Some lore
Incredible spoilers incoming, you have been warned. Also, I'm writing this off the cuff before a shift at work, so forgive any inaccuracies. Feel free to correct me and I'll fix it here, but I believe I've got this down pretty solid.
In the Age of Fairy Tales the Master of Masters devised a plan that would trap the pure elements of Darkness, sentient creatures with unknown pre-history origin, for good. Only, it would require the destruction (and rebirth) of everything.
He wrote the Book of Prophecies and handed it out to multiple Foretellers, who found Unions. It revealed the future that would end in a Keyblade War that was inevitable. The Foretellers were charged with gathering Keyblade Wielders and sending them out to Datascapes (Disney worlds) created with information about future worlds to gather light. However, the Book warned of a traitor, and each Foreteller was given a task.
It was all a plot to make everyone ultimately fight amongst themselves, and thus trigger the Keyblade War. It all went according to plan. You, the Player, get caught in the middle of all this. One Foreteller, Ava, was charged with creating the Dandelions, a group of Keyblade Wielders that would hide in a Datascape and survive the world being consumed by darkness.
However, that Datascape was meant to be a prison for the physical embodiments of Darkness. The Master of Masters' plan almost succeeds, but one Darkness escapes while hiding in Ventus (yes, the same Ventus from Birth by Sleep), who isn't even supposed to be there. The method of escape involves time travel to the future, not getting into the how or why, just trust that it works.
The Darkness had used Ventus to murder Strelitzia, Luriam's (later Marluxia) sister, steal her position as a future Union Leader, and escape from the destruction of the Datascape. Ventus appears unconscious in the Keyblade Graveyard before the events of Birth by Sleep.
The others that escape are Ephemer, Luriam, Brain, Skuld, and Elrena (later Larxene). Oh, before that, Maleficent also uses a pod to escape, which triggers the destruction of the Data Scape in the first place. Oh boy do we not have time to get into that here.
We know what happens to almost everyone that escapes in the pods: Ephemer builds Scala ad Caelum from the remnants of Daybreak Town, Luriam and Elrena join Organization XIII in a quest to find out if they can recover Strelitzia, Brain wakes up in Scala ad Caelum and Skuld's fate isn't shared. All signs point to Skuld being the girl that Lea and Isa meet in the basement of Radiant Garden, a plot point that should become significant in Kingdom Hearts 4.
The Dandelions left inside the Datascape don't escape its destruction, but are able to choose to be reborn later in the real world as a part of new hearts or turn into Dream Eaters (see Dream Drop Distance) to aid Keyblade Wielders in the future. Player, who never joined the Dandelions, was there because they were rescued at the end of the Keyblade War.
Instead of becoming a Dream Eater, Player chooses to be reborn as a new heart.
When Player is reborn, they awaken in Scala ad Caelum and find baby Xehanort, a descendent of Ephemer who was friend of Player. When Player dies of old age on Destiny Island, Xehanort's story truly begins. (See Kingdom Hearts 1-3)
Connecting the pieces
Why am I sharing all of this? Because the events that lead to the end of The Age of Fairy Tales, orchestrated by the Master of Masters, ties to the creation of Scala ad Caelum.
The Master of Masters hides in the world of Quadratum, a fictional world where time moves differently from the "real" world in Kingdom Hearts. He appears from time to time across the ages to ensure his plans are being carried out, including manipulating Xehanort.
Ephemer built Scala ad Caelum and is the ancestor of Xehanort. One of the new Union Leaders, Brain, that survived the Datascape destruction in a pod, wakes up in Scala ad Caelum three generations later and is greeted by Sigurd, a character we've never seen before.
Sigurd later appears in the official Kingdom Hearts 4 trailer. Also, Brain is in the leaked opening video of Missing-Link. We now know without a doubt where that canceled game would have taken place – at the hight of Scala ad Caelum.
The leaked video
Okay, given everything I've shared above, I'm going to share my thoughts in the order provided by the leaked video.
There is some excellent opening music and suspense showing suits worn by Keyblade Wielders. Darkness, in this case, is represented as a liquid sphere that appears in Quadratum. The tubes coming down aren't supplying oxygen, but Light.
Given that this game takes place three generations after Ephemer builds Scala ad Caelum, these are clearly the precursors to the Keyblade Wielder suits worn in Birth by Sleep.
I'm not going to get into the Keyblades we see here, though some should be familiar. This scene represents player characters taking on a raid boss (I assume), which would have been an aspect of the game. We see several wielders die in the battle, but they are ultimately triumphant.
Obviously, there's lots of oddities represented by this scene that could be contradicted by the Kingdom Hearts 4 trailer, but here's my thoughts on this.
Ava clearly found out where the Master of Masters was hiding and followed him into Quadratum. Their appearance in that world introduced Darkness. Time flows differently there, which is why Ava and the Master of Masters can still be alive in the far future where the Kingdom Hearts main timeline exists.
Darkness has existed in Quadratum since the Age of Fairy Tales (real world time) which could be only weeks or months in Quadratum time. So, the idea of Keyblade Wielders from Scala ad Caelum being in Quadratum three generations after the Age of Fairy Tails isn't impossible.
Why they are there is a mystery the plot of the game might have revealed, though it's clearly connected to the events of Kingdom Hearts 4. My guess is research and the goal of Scala ad Caelum, which might have been the eradication of darkness.
Anyway, on with the opening video.
After that intense battle in Quadratum, we see a series of scientists in white lab coats walking in the empty hallways of what could be an office building. The scientists are similarly designed to scientists working for Ansem the Wise and later Xehanort's apprentices.
A scientist leaves the white hallways and emerges in the central room of Scala ad Caelum's main castle. He hands a letter to a courier, who takes it to a guard, who takes it to another guard, who then takes it to what appears to be yet another courier near the external access of the main castle, who then takes the letter to what is likely the player character for this game (not to be confused with Player from Union Cross).
The letter is most likely an assignment to one of the missions you take on in the game.
We also see an early version of the heart sigil that would one day be used by Xehanort.
A voice (Brain's?) says the following:
The era missing from history's cycle – As people and Heartless endlessly emerged from the distortions, it was the third generation of the founded city that faced the true nature of this phenomenon.
Light and darkness brought about the beginning, and hearts nurtured it. One generation succeeded another as time flowed on – until the world that came to be was filled with thriving people.
This is a city of light and darkness, kindred and kinless, dreams and distortions – the metropolis Scala ad Caelum.
On the night that you opened your eyes in this world the stars – beautifully distorted – rained down from the pitch-black sky.
These distortions are what we saw at the beginning of the video and are obviously what would be the target of you, the player, in this game. The beginning of course is what occurred after the end of The Age of Fairy Tales.
I really hope that one day we get to experience this chapter of the Kingdom Hearts franchise. It clearly was going to be a very important piece of the puzzle for explaining how we get to Kingdom Hearts 4.
The story lines up. This all fits and makes sense. I expect Missing-Link would have shown us descendants of Ephemer, who might have been grandparents or even parents to Xehanort, though I'm not sure. It seems that when Player shows up in Scala ad Caelum, it’s far enough into the future where Brain would have been long gone.
I assume Sigurd has some connection to Luxu. Luxu survives the long period of time between the Age of Fairy Tales and present day by placing his heart in new vessels. The latest one we see in Kingdom Hearts III is Xigbar, or Barig. Which I always thought was weirdly close to "Brain," though they are clearly different characters.
Sigurd isn't Luxu though, but perhaps he's tied to the darkness in some aspect, as his eyes appear to be the yellow color associated with being "Norted" or tied to darkness.
I'm sure there will be plenty of analysis on this single video for months to come. I'm excited for Kingdom Hearts 4 and hope that we can get more content in the meantime.
Perhaps we'll finally get the "All-in-one" collection for PS5 with every game and cutscene library put together. I assume we haven't because they've been working on a cutscene library, or even re-built CGI cutscene movie, for Missing-Link, which would be included in this "All-in-one" bundle, exclusively of course.
I would like to think that's why we're seeing this now and not back when the game was canceled or in beta. It's the same property, but a product being prepared for a different release.
Time will tell.