Adapted from the song "The Villain Career of the Eldest Lady and the Eldest Master", with some changes in the plot.
She is a cold-blooded and delicate eldest lady.
He is a narcissistic young man.
…
Two years ago, a brother and sister whose names were only known but whose identities suddenly appeared in the world suddenly appeared. They control the world, are at home all over the world, and kill with skill. The world calls it the "double wall killer".
But no one knows why they came, why they drew their swords, and why...
Become a demon and become a Buddha.