My Accidental Husband is a Billionaire！ - Chapter 4 - Granddaughter-in-Law

Nine heavens and nine earths, there are many souls.

The strong stand in the nine heavens, like shining stars, while the weak creep on the ground like tiny ants.

The young boy Bai Ye accidentally unlocked the mysterious heavenly soul, cultivated supreme soul skills, guarded the soul and sword, rushed into the nine heavens and swept the stars, and the legend began…

- Description from MTL

The world was once at war with 10 alternate worlds. This was known as the Concept War and our world won 60 years ago. All of this was concealed so no normal people are aware of this fact in the current time.

After the death of his grandfather, the high-school student Sayama Mikoto is suddenly summoned by the giant corporation IAI. He learns this world is headed for destruction due to the acceleration of the Minus Concepts. To prevent this, negotiations must be undertaken with the survivors of the other parallel worlds so their 10 concepts can be released.

And so Sayama is caught up in the final battle to clean up after the Concept War which left behind so much enmity.

A hundred years ago, Chen Qingyuan entered a forbidden zone called Sky Abyss, where his soul lamp extinguished, and everyone believed he had died. Today, although Chen Qingyuan has emerged alive from the forbidden zone, his cultivation has been completely crippled, and his spiritual roots are shattered. Faced with the remorse of lost love and the oppression of various sects, how should Chen Qingyuan proceed?“Chen Qingyuan, I'll give you two choices: one, marry me; two...”Inside Sky Abyss, there lives a girl in a red dress, with eyes like stars and a gentle voice.“I choose the second option.”Before the girl in the red dress could finish speaking, Chen Qingyuan decisively made his choice.(Main character with a dark belly + no system + humor + traditional fantasy + weak synopsis)

Reborn as a sword, he lived for hundreds of years, and then he occupied the body of a 15-year-old prince.