Timeless Assassin - Chapter 74: Ghost Sleep.

This novel is also known as I Possessed a Demon Sovereign

Chen Luoyang felt that something was wrong with his transmigration. After transmigrating, he possessed the body of the highest expert in the world, the Master of the Demon Cult, addressed respectfully as the Demon Sovereign.

Generally, aren’t supreme experts the ones that leave behind a wisp of their soul behind and occupy a new body of some miserable low-level youngster then they go on a journey of revenge and make a comeback?!

Or perhaps it would be transmigrating into a miserable youngster’s body and obtaining a cheat slowly walking the road to becoming a God?

But why did his transmigration seem wrong?

Now my environment is full of big shots and I feel like I’m going to be exposed!

- Description from Novelupdates

Park Moonsoo worked REALLLLLLY hard in life before dying.

She went out of the way to help him build a business empire and get his inheritance. When she thought they would live happily ever after, she and her entire family were quietly gotten rid of and burned to ashes. As the blaze seared her skin, she was overcome by deep hatred and bitter regret, and wished she had another chance…

Dizziness jolted her out of unconsciousness.

She is now known as Miss Su. She tried to run from her wedding, but slipped and fell in the river, which incidentally, brought great shame upon both her and her fiance’s family. The word on the street is that her fiance is a playboy, a make-out king, and a bit of a lady’s man. But she has to salvage this marriage to carry out her revenge plan.

And… the more she gets to know her future husband, the more she needs to find out. He turns out to be much deeper and more sophisticated than he cares to show to the outside world.

- Description from Novelupdates

The protagonist, having degenerated into a “loser” after being unable to find employment, gets caught up in someone else’s attempt to commit suicide-by-train and ends up traveling to another world. The numerous cheat powers he demands from God are all granted to him. But contrary to expectations, these powers bring about disastrous consequences for the protagonist.

Having reincarnated into another world, the optimistic protagonist (Yuuri) starts his(her) heart-warming training days with his(her) teacher.