SMT/Persona timeline split and the absence of demons

Okay, spoilers for... pretty much all SMT games from hereon, Persona included. Also, this is long and rambly. You have been warned.

So I've been playing Devil Summoner: Soul Hackers recently and I've been wondering about how this all fits together. I am aware that Atlus makes all these games as stand-alone as they can be, but still, several games are confirmed to be within a single continuity, so there's this one thing I've been wondering about that's missing in newer Personas - namely, demons.

So we know that thanks to Raidou Kuzunoha the 40th and time-travel shenanigans, we have two main SMT timelines - the classic SMT timeline with the apocalypse and all, and the SMT if... timeline where the cataclysm never happened.

I think at this point it's safe to say the Persona and Devil Summoner games all belong in the SMT if... continuity. First of all, all Persona games are confirmed by the creators to take place in the same continuity. 1 and 2 are clearly linked, with recurring characters even, P3 has the Who's Who show that gives us info on where the P1 and 2 cast are now, and in P4 you visit Gekkoukan High and get call-backs to the previous game. And, of course, Persona Q confirms the connection further.

The link with if... is the most clear in P1 and P2, where we get the character of Tamaki, the main female protagonist of if..., who even subtly references the events of her game, meaning Persona 1 happens not long after SMT if... (which is also considered a proto-Persona gameplay-wise, as it introduced many elements that would carry over into Persona). Tamaki is also our link to Devil Summoner, as in both of the Persona 2 games, she works for the Kuzunoha Detective Agency. Kyoji Kuzunoha is the name of one of the main characters of Devil Summoner, and he's a body-surfing detective by the end of the first game, and it's strongly hinted that in Persona 2 he inhabits the body of detective Todoroki. Additionally, I think it was Naoto in Persona 4 that mentions the Kuzunoha clan. At this point, I think the evidence is overwhelming that SMT if..., Devil Summoner, and Persona all take place in the same universe. It helps that all these games have a similar tone, which is much lighter and more hopeful than that of the mainline SMT games.

Now here's where things get tricky. Where are all the demons in the newer Personas?

In the Raidou Kuzunoha games, which take place in 1920s Japan, demons are most certainly all there, just not visible to most. Since this takes place decades before the invention of the COMP and Demon Summoning Program, communicating with demons is much more spiritual, with Raidou undergoing special training to do it. I have not played SMT if..., but I understand this could be a similar case to Persona 1 where the demons overrun the real world because of somebody's actions. In the Devil Summoner games, you encounter demons all the time, but that's because you keep running into people who can summon them just like you. I figure the Demon Summoning Program just gives shape to the demons that are invisible in the human realm but are still there?

Persona 2 kinda complicates things further due to another timeline split. I don't know how Eternal Punishment ends, so I don't know what exactly happens to the demons after it, but even if the Eternal Punishment timeline is the one 3 and 4 follow up on, even Eternal Punishment had Tamaki and Kyouji in Todoroki's body, so that timeline is still linked with SMT if... and Devil Summoner. I know that the Shadows appear in 2 for the first time, but they are different from the mindless creatures that are random monsters in 3 and 4, and appear more similar to the other selves in Persona 4.

So how did Shadows get born? And where did all the free-roaming demons go? I have not played the Arena games, but I heard there were strong hints that Nyarlathotep was at it again, which were later completely thrown out the window. So does Arena offer any more insight?

And this brings me to Persona 5. We see that demons are back as enemies, but it looks like they're still confined to the other world, rather than the real one. It's also interesting to note that this is the first Persona game to take place in Tokyo, just like most main SMT games do. I know P5 is gonna be as stand-alone as it can, and I'm glad, honestly, because this timeline is pretty messy, but I am interested if we'll get any more subtle hints linking it to other games within the subseries and outside of it or not.

The easiest solution is that Persona is a reflection of the SMT universe in its true form and thus demons are only as real as people want them to be and thus YHWH and Lucifer only exist because enough people believe they do. This is often confirmed in the actual SMT'Verse as there are several stories within the games that confirm that demons and gods powers and even their existence is based on the power of belief humanity has in them. It's interesting to note how the only ending in the series that actually ends the conflict between Law and Chaos for good is the only one that involves mankind's complete extinction. In all other endings, mankind always exists in some form, so it's highly likely that the universe is maintained by mankind's belief in it.

The thing to point out about the Persona games is that none of them ever featured actual demons. The demons in P1 are the creation of Maya in the machine Kandori used to try and rewrite reality to become a god, demons only exist in P2 because Nyalarthotep's power to make rumors come true allow for all forms of creatures to become real again. The only area this gets complicated is whether Nyx, Erebus, Izanami, and Hi-no-Kagutsuchi are actually real (and thus demons do still exist in the Persona-verse but in limited form) or if they too are simply manifestations of mankind's hidden desires.

There are still parallels between both series as most SMT conflicts are often started due to mankind's own misguided need for an apocalypse in the classical sense. The deciding element that differs the Devil Summoner/Persona timeline with the main SMT one is that the former tends to be a more hopeful existence, with mankind only subconsciously desiring something more whereas SMT tends to involve people actively starting the end of the world. With this mindset, it's possible that either all demons, gods, and mythological beings are simply the psychic manifestation of mankind as Persona suggests, or its possible that they are real, but because so few humans know how to actively engage in them and the world is largely more optimistic in spirit, that these beings have more limited power or less desire to bother this timeline unless provoked.