As these are WMG, all spoilers will be unmarked ahead. You Have Been Warned!
The survivor count is used to let Tengan know how many are still alive in the killing game. The count itself is electronic so it doesn't stop when/if he dies. The bracelets keep track of vital signs and such and decrease the count when death is detected.
Hagakure is an unknowing participant even without a bracelet. The helicopter that tried to kill him is an alternate way to keep track of his survival. If Hagakure was successfully killed the copter would have sent that data.
The Miaya in the game is a robot originally controlled by Monaca before going autopilot. If the robot ceases functioning that counts as a death and decreases the count.
At episode 10 the count is at 6. At episode 11 Juzo is revealed to be still alive but with his arm was cut off. We are meant to assume that Kirigiri is well and truly dead. However, under my theory it can be said that the bracelet still detected Kirigiri's vital signs and Juzo's bracelet falsely reported him dead because he was no longer wearing it.
Could be either the AI, the original, or maybe even both, since the AI establishes they're separate people. For the AI, while Hajizuru was working to revive his comatose classmates, he could have downloaded the AI into his own head to keep her there temporarily until he or Kazuichi could build her a body, or she might have fused with him accidentally during the final trial of SDR2. For the original, Absolute Despair Girls showed that ghosts were a thing, and with all the talents he has being a medium of some kind doesn't seem out of the realm of possibility. So when she says she'll always be with him, it's not just an exaggeration.
Since the first episode, it was said there were 16 survivors. As people started dying, the survivor count naturally started going down. However, there were a few questions raised about this. Number one, there seemed to only be 15 participants in the Final Killing, so the 16th participant seemed to be either Hagakure or a hidden character. Number two, the fourth round appeared to have a total of four deaths: Kirigiri, Sakakura, Andou, and Mecha-gahara. However, the next episode revealed the counter only went down by three, meaning one of those people must have survived, or the robot's death didn't count (which would also mean there's another hidden participant, but...). However, we find out later that not only did Sakakura survive, but Kirigiri never actually died; so, by all rights, the survivor count should only have gone down by two. So, here's where the WMG comes in: During the fourth round, it's possible either Kirigiri or Andou were in a very early stage of pregnancy at the time of their deaths, and the survivor count was accounting for the unborn baby. If Andou was pregnant, there's no way the baby could have survived Andou's rather gruesome demise. If Kirigiri was pregnant, it's possible that the drug she used to prevent her own death was enough to save her, but not the baby.
- If it is, the narrative would have said as much or hinted about it.
- Two possibilities: Juzo's bangle considered him dead because it no longer detected his life signs (making him "dead"), and Mecha-gahara was spoofing her life signs until her destruction. There's your three deaths: Sakakura (lost signal), Andou, and Mecha-gahara (lost signal).
Of all the central protagonists in the storyline, Munakata stood out as the one that didn't achieve any real sort of final resolution to their story arc and whose future stood out as overly ambiguous in contrast to the others. Chances are the man's journey hasn't ended yet and there's still a long road ahead for him to atone for the mistakes he made during the Final Killing Game and while under Chisa's influence.
Monaca seemingly decided to leave the planet for good, but Komaru seemed entirely unconvinced that she was going to stay up there forever. Considering how sudden her exit was on the heels of all the buildup that occurred in Ultra Despair Girls, it's arguable that her quick exit was brought about by time constraints and she may still have a purpose to serve ahead in the Gifted Inmates saga in some form.
He didn't start the Final Killing Game in order to get Ryota to brainwash the world with his hope video. This was never said by Tengan himself. This was only inferred by Kirigiri and the others. His true reason was for the sake of despair. We see Chisa giving him both the suicide video and the brainwashing video. What if he watched the brainwash video and fell into despair? This would fix a majority of the holes in his plan, namely why he kept Ryota in the game and why he didn't just ask him to use the hope video.
- Killer Killer seems to support this, with Tengan being shown with the swirly eyes that indicate despair.
It would explain why he left Ryota in the game, as he could rely on his luck to keep Ryota alive even if Tengan himself died. He might not have been officially recognized as having Ultimate Luck because it wasn't officially considered a talent by Hope's Peak until after he'd graduated high school.
- Also, if this is true, Naegi would be a Legacy Character as an Ultimate Lucky Student who became headmaster of Hope's Peak.
The old man is fast for his age and says he's a fifth-dan in kendo, and generally seems to know more than he lets on.
Hence why he showed up unexpectedly.
As the SHSL Therapist involved in the New World Program, her personality may have been coded into there (by herself, Chihiro, Matsuda, or some combination of the three) to best guarantee its effectiveness. Whether Usami actually is Miaya (in terms of a copy of her at the moment of implementation) is anyone's guess.
The brainwashing videos were so terrible that the viewer could be Driven to Suicide, right? That would mean the viewer would also fall into despair to want to do it... But, what if they were made less effective so they wouldn't cause said suicide? Well, that would end up converting the viewer over to Ultimate Despair. She likely wanted Tengan to show the other Future Foundation members those videos so they could fall into despair like her and make "the world's true last hope" (the Future Foundation) fizzle out.
The only thing we know about them is that they missed the hearing for whatever reason and sent Asahina in their place. Since said hearing ended up killing most of their fellows and it's highly unlikely they could've known about Tengan's plan beforehand, that makes for quite a stroke of luck. There's also an Ultimate Lucky Student in every year, so it stands to reason that one of them might have joined the Future Foundation and been made a Branch Head.
