First of all, you have to know Mihoyo have a game called Honkai Impact before, according to the setting inside, when people's technology is more advanced, it will trigger the so-called Honkai. And Honkai will destroy human civilization. In the story of Honkai Impact, it has been confirmed that Genshin Imapact is a parallel world with the same rules.

So the story is like this. About 3000 or even earlier, Teyvat was almost destroyed because of Honkai. At that time, some people sacrificed themselves to protect the world. These can be read from Venti's poems (but this paragraph It seems that in the comics, Mihoyo’s tradition, the plot is half in the comic and half in the game). After that, human civilization has also regressed substantially.

Because of this disaster, the ancients began to fear the development of civilization, so they made a sky island system. The function of this system was to select seven gods and let them manage human civilization, so that the world would not be destroyed by Honkai. Since then, the gods who symbolize the seven qualities have been selected: freedom, contracts, eternal, wisdoms ,justice, war and love.
Make another irresponsible guess on this person. The god that appeared at the beginning of the game should be the main god of Sky Island, used to manage other gods' work. And it's very likely Paimon. All the gods in this game are named after Ars Goetia. There are Barbatos and Morax and Paimon in the story up to now. So how could she be just an emergency food.

About 500 years ago, a new country appeared, which was the last country in this video, Khaenri'ah. This country quickly developed a high-level civilization, and many places on the map have the remains of this country. However, according to the rules of sky island, this country have to be destroyed. So the war began.

What can be confirmed is that all the seven gods should have participated in this war and had an impact on several gods. (There is a description in the other PV. Most people have not seen Barbatos for a thousand years, but only one person has not seen him for 500 years, indicating that someone has seen Venti 500 years ago. When the war broke out)

The ending can be imagined, the Khaenri'ah was defeated by the gods, and their people were cursed and turned into monsters, namely hilichurls and abyss mage. But they left some uncursed descendants, such as the new character  ​​that appeared in this video and kaeya.(So kaeya ​​and amber will be strengthened sooner or later. Amber has a very strong potential in comics, so sooner or later Mihoyo will come up with a new Amber.) These descendants should exist for revenge and fulfill their ideas.

The idea of the Khaenri'ah people can be found in this video, that begin at 3:00 , "in the perpetual meantime of a sheltered eternity, most are content to live, and not to dream. but in the hidden corners where the gods' gaze does not fall, there are those who dream of dreaming. some say a few are chosen and the rest are dregs, but i say we humans have our humanity. we will defy this world with a power from beyond." Although most of them have become monsters, they still challenged the god, the sky island, with human identities.

So it can be understood why another traveler wants to help the abyss.

Turning back to the seven gods, after the war, several gods began to reflect on the correctness of the sky island.

Among them, the biggest action is the god of cryo, she is also the god of love, and she has seen too many people lose their lovers in the war. So she established the Fatui organization, she distributed her power to her subordinates, she abandoned her identity as a god, and together with her followers, she prepared to challenge the sky island.

In comparison, although the actions are not that big, the god of freedom, god of contracts and god of wisdom all show resistance to the sky island rules. Is freedom at the mercy of sky island still freedom? Can a forced contract really be called a contract? Since the development of civilization is a folly of self-destruction, then what is wisdom?
So the narrative in the video appeared, Venti allowed Mondstadt to be completely autonomous by humans, he no longer interfered, Zhongli ended all contracts in Liyue, god of wisdom ignored the so-called "folly" of scientific research and cultural development in Semeru.

Some people will resist and naturally some will comply. You can know from the video that god of eterna and god of justice still abide by the rules of sky island.

And God of war can't see her position from the video description, may resist or continue to comply.

Yes, according to the comic, she is probably a female. Coupled with Mihoyo's consistent "lazy behavior", it is likely to be Himeko's modeling. :)

(Finally, the above content is purely inferred from the existing conditions, and may not be correct, it is only for reference.)

PS:There are many hidden stories in the books, weapon descriptions and artifacts descriptions in the game. You need to read them together to make a complete story. It's worth exploring.