MTL - Law of the Devil - Chapter 627 [Small emperor acting]

Thirty-three classmates hold a reunion after graduating. Tensions soar and old friendships are tested, as a strange turn of events lead them to follow the path of the ancient gods.

Our protagonist Caam is a man from Earth that was reincarnated into this world as a demon. In order to survive, he spared no effort in avoiding the sparks of battle and without noticing it, he became strong himself.

“I’m in desperate need of money to pay Grandmother's medical fee. I will marry Charles instead of Yvonne as soon as I get the money.”

When her sister Yvonne ran away from the wedding, Autumn was forced to pretend to be Yvonne and marry Charles. Her only wish was to get a divorce after a year. Charles is rich and powerful. His name had been linked to innumerable ladies. He had different girlfriends for every day of a year. Neither of them had expected that they would fall in love with each other.

The formless ancient world was infested with despicable demons. They hunted and feasted on mankind, keeping the human civilization constantly in a weak and suppressed state.

During the first known year, a magical mountain descended into the world from the realm of the Gods. Carved on this enormous mountain was a message: ‘Heaven Prevails’…

After the Grand Descent, a name that was given to the descending of the mountain, the Three Great Sages made their ways to Mystic Mountain where they learned to harvest what we now call magic, establishing the Mystic Cults and eighty-one sacred shrines to help aid mankind with the cult’s mystic powers against the eternal fight to the death with demons.

- Description from Novelupdates