There are seven different elements in Teyvat, and behind each one stands a corresponding god and elemental dragon sovereign.
Mondstadt, the land of the Anemo Archon, has Dvalin. Liyue, the land of the Geo Archon, has Azhdaha. Sumeru, the land of the Dendro Archon, has the Dendro Dragon...
But Inazuma, the land of the Electro Archon, has only the Raiden Shogun. It is missing an Electro Dragon.
Some say the Raiden Shogun slew the Electro Dragon. Others say it went into hiding, unwilling to show itself...
Then the arrival of a visitor from another world unexpectedly caused the Electro energy throughout Inazuma to resonate as one, and at last, a dragon sovereign unique to this land was born.
“Ding-dong. Heavenly System at your service. Please claim a base as soon as possible to bind it to yourself.”
Hearing the voice in his ear, Lei Tian, who had just transmigrated and become the new Dragon King, stood at the edge of a cliff and gazed down at Watatsumi Island. Farther out, the ocean stretched as far as the eye could see.
(This is the story of a newborn Dragon King’s growth, until he becomes the ruler of Inazuma and even the entire world.)
Putting aside details such as combat power issues, it's okay.