In My Favorite Novel As The Final Villain - Chapter 169 -

Name: ParadoxSpecies: Snake, ?Description: A tiny snake with great potential.That was who I was. That was what I was. A tiny snake with great potential. The sole creation of the Great Core.It was just us, the Great Core and I, tucked away in our little corner of the World Dungeon. Together, we hid from the bad-things and the Coreless of the world outside - safe from the horrors that would consume us.Until, one day, the Coreless found us. Until they tried to steal away my creator. Until, with no other option, I swallowed the Great Core that had made me.Only after that did I become what I was always meant to be.At last, I became the Great Core's Paradox in more than name.[The Endless Cycle] began.Thus begins the story of a little snake zealot and his journey to greatness.

As a promise, he went out into the world as an assassin. 3 years later, after becoming the Supreme Assassin, he gave up on everything he had and returned to the ranks of ordinary people. But one day, Kismet, a mystical game created by the National Research and Development had appeared.

One day, Luo Jian woke up from his sleep and found himself in a locked chamber where the door and window were all sealed. A note with a few lines written on it was tacked to the wall: “Escape from this room within an hour, otherwise, you will die.”

There is a sequel called Reincarnation Night (轮回之夜) that takes place in the same universe but has different main characters

- Description from Novelupdates

The once greatest Saint underneath the heavens has been reborn after one hundred years. He cultivates with mighty skills, and he fights to once again reach the top of the world!

Don’t compete with me when it comes to concocting pills, 100% effectiveness means nothing to me.

Don’t compete with me when it comes to cultivation speed, I won’t be responsible when you die from embarrassment.

Don’t compete with me when it comes to experience, as I’m an ancient ancestor.

The existence of Jiang Chen is destined to ridicule thousands of geniuses…