Duke's Quadruplets Are All Overpowered

Quadruplets were born in the Rainberg family!
All the children were unusual.
The firstborn was the ruler of Murim.
The second was Demon’s ruler.
The third was an angel that descended from heaven.
They were all the invaders who tried to invade Earth in their previous lives,
“Who were you?”
As the youngest, I…
“Cantavia”
I was someone that protected the Earth.