Real natural disaster

During the drone strike Toujirou tells Valentina and Maricarmen that all the disasters occuring in phase 1 are just a rain ceremony, human actions meant to summon a real natural disaster.

This is the complete opposite of other when they cry entries where we are told that the culprit behind the events is supernatural: Oyashiro sama's curse, The witch Beatrice. Here we are told without any hesitation that there was nothing supernatural about the events of phase 1 and the intent is to summon an actual supernatural force.

Toujirou compares these disaster to an invitation for someone to play chess. Moving the pieces to signal to whoever might be watching that the game has started.

The three kings also talk about an opponent they are awaiting

So everything that happened in phase 1 was not the actual game, it was just preparing the gameboard.
In the very last scene of ciconia: Data Fragment 16, Seshat says that after everything, humanity has just managed to get it's opponent to sit at the game table

3.5 billion people were killed in phase 1, yet this wasn't even part of the game, just preparation for it. It's as miyao said

"There's no way that natural disasters that might happen once per millenium would all conveniently happen at the same time!

It's weird enough that a world war -- only the fourth one humanity has ever had -- would conveniently take place!

And it just happens to coincide with a modern earthquake on a global scale?! The biggest superearthquake disaster in human history?!

And because of the negative side effects of that, there's also global cooling? And a worldwide famine? And then comes the simultaneous global revolt of drones?!"

and this:

Most likely, these natural disasters weren't even aimed at us! We're just getting pulled in and tossed about...!!

It's like a ritual, the goal is not the act of destruction and killing itself but to show it to somebody. A performance.

In the Data Fragment Seshat reveals that the opponent of humanity will use the book of revelations to carry out the world's destruction. We already saw parts of it being fulfilled in phase 1, such as, the drone strike killing a third of mankind, the four horsemen, erbil L5 and wormwood falling from the sky.

But didn't Toujirou say that everything that happened in phase 1 was the action of humans?

The Humanity's opponent will destroy the world in accordance with revelations, but it's actually human pieces who carry out parts of the prophecy, specifically the three kings.

Seshat is very concerned with stopping the opponent of humanity but she doesn't really mind the three kings, after all, she says that even though her order and the order of the three kings went their seperate ways, their goals still remain mostly the same. Even though the three kings cause mass death and destruction they are on the side of humanity, trying preserve it and prevent civilizations end. 

That causes a contradiction.

The opponent of humanity uses the book of revelations to destroy humanity -> but the three kings who use it are not the opponents.

They say this:

"We must make use of God's plan to return the fate of humanity to human hands"

God's plan = The book of revelations

The three kings intend to use it to help humanity while humanity's opponent wants to eradicate it. This ties into what Toujirou has said, Human actions pretending to be natural disasters are meant to summon a genuine natural disaster (God's representative). Initializing the game.

Legend.

In all previous wtc games there is a pattern of humans gaining supernatural power by imitating a legend in higurashi The curse of oyashiro sama is a pattern of one person being killed and one person disappearing every watanagashi, because of this pattern people 'expect' the pattern to continue, creating an environment where if someone wants to murder someone, they will do it on the night of the watanagashi.

And the person who carries out the curse becomes Oyashiro sama's (God's) representative, since it's oyashiro sama's curse.

Takano used the curse to gain power by killing the entire population of Hinamizawa on the night of watanagashi, effectively becoming Oyashiro sama, a God.

In Umineko on Rokkenjima there is a Legend of the Witch Beatrice, of which everyone in the family and the servants are aware of, unlike Higurashi there isn't a pattern of the same thing happening every year but there is the witch's epitaph.

when murders occurring on the island match the description on the witch's epitaph then the person carrying them out becomes Beatrice sama, because the observers on the island are aware of the epitaph and associate it with the witch. The more people believe the more powerful the magic and the witch become.

In both the culprit uses a legend to deify themselves, to have that happen you need:

-an established pattern tied to the supernatural

-observers who are aware of the pattern 

-carrying out the crime in a ritualistic way.


Now everything toujirou said about humans inviting the opponent makes sense, the plan is this:

Create the pattern by carrying out the events in the book of revelations, by showing the people this pattern someone will notice it as an invitation to 'play' and try to deify themselves, taking the role of God carrying out divine judgement: God's representative. If you initiate the pattern the rest of it will carry itself out on its own.

The real natural disaster that they are trying to bring is human pattern recognition.

Because of it it's impossible for them to know who the culprit will be as it can be anyone on earth and even if you kill that person someone else will take their place, there might even be multiple simoultaneous culprits. To truly defeat them you would have to destroy the pattern, environment bringing disaster not just one individual person.

The one problem making this much more complicated is... that the book of revelations doesn't exist in A3W, as Seshat says it was completely erased.
In Higurashi the villagers are aware of the curse and expect it to be fulfilled every year.
In Umineko the people on the island know about the epitaph and notice they are dying in accordance to it.

But at no point in Ciconia is anyone like: "All these disasters are just like the book of revelations"

If there are no observers aware of the pattern there is no power to be gained from it and you might just as well be doing random meaningless things.

well the answer to this problem might be simpler than you think.

The only people who know about the prophecy of the book of revelations are toujirou, seshat and one more person.... who is both one and possibly tens of thousands, a replaceable one. 

"i am one yet many"