Kyoukai Senjou no Horizon - Volume 8A, Chapter 5: Cancelers All Around

[Hiddenidentity, Femalelead, Loveaftermarriage]She originally planned to take her sister's place and marry a 60-year-old man, but accidentally married him, who was the richest man as he had also made a mistake. She thought they would soon divorce, but he chose to temporarily maintain the marriage.The public disliked her because of her ordinary background and believed that she was not worthy of him. However, her multiple identities were gradually exposed: academician at the National Research Institute, a brilliant doctor, the racing god, national representative of Go, and gold medalist in figure skating. And when the world found out that their marriage was only contracted for one year, she garnered numerous suitors. “Get out! We will never divorce! Never and ever!” he declared.

The mortal body, metamorphosis, longevity, immortality, and eternal life. These five realms, step by step, reveal themselves in front of you. As a normal person, how can one try step by step to reach and open the door to eternal life?

Between the heaven and the earth lies the mortal body, the mysteries of metamorphosis, freedom of longevity, the power of immortality, and the hope of eternal life. A story filled with endless new magic, a new world of immortal styles, people, demons, gods, fairies, magic, kings and emperors. A world of love and hatred, revenge, and mystical battle, all in “Eternal Life.”

- Description from Novelupdates

One day, I woke up only find out that I’d become a Demon Lord, an individual responsible for protecting a dungeon. The world I’d been spirited away to was one filled with violence. Gigantic monsters wandered through it and competed with each other each and every day for the right to survive. I had no choice but to strengthen my dungeon’s defenses in hopes of living another day—or at least that was what I’d thought. For some odd reason, I instead ended up spending my days in relaxation and bliss.

There are two gods in the world, one lives in people's hearts and is dead. The other lives in reality and is alive.He is a person, he is named God. Yes, he is the one being talked about.He has returned from Hell.