MTL - Happiness Consist in Contentment - v7 Chapter 2

In a modern world, a professional assassin was murdered by her beloved and found herself revived in an ancient world as ...In a modern world, a professional assassin was murdered by her beloved and found herself revived in an ancient world as a general's daughter with a weak physique. She was engaged to a prince, but because she did not have a nice appearance, her fiancé and sister attempted to kill her. Although she had to struggle to survive, there were also those who unconditionally loves her that supported her in her time of need.How does she intend to adapt and survive in such a foreign and hostile world? Follow Gu Xijiu on her journey to discover her one true love!

Year 2099, the world as we know it now advanced in technology. Learning has become easier, and so is transportation. But in this new advanced world there is undoubtedly problems, beings who want to use the new technology to bring chaos and strife to humanity. Xander, a 17 year old normal High school boy buys a new MMORPG game and through it, he improves his skills in all aspects. He lived a normal life until one day when his father, who abandoned him and his mother for a year came back, claiming to be the leader of a group of super humans. This was the day Xander’s life changed. He was told he will get a power to stop the enemy but what will it be? Is he even ready to take on such a responsibility? Nobody knew that this enemy group were in charge of G. CO, the creators of League of Guardians virtual MMORPG game. What they plan to use the game to accomplish was... absurd... but anyway, read to find out. Let’s Follow Xander on his journey as he becomes the strongest Super human and save humanity from doom. ... [You have killed level 51 reaper] [Do you wish to demonify, level 51 reaper?] “Yes.” [You have created a new demon, Lich] The ability to create demons from dead creatures. With this power he shall defeat his enemies and get his peaceful life back.

The scum’s or villain’s long road of transformation was tentatively set to the world:
The abandonment of the educated youth’s wife (Completed)
The hidden marriage of the scum film emperor (Completed)
The best brother in the world (Completed)
The Phoenix male who destroy the bridge after crossing the river (Completed)
The treasonous general (Completed)
I’m an honest man (Completed)
To become the top scorer in the School of Agriculture (Completed)
The soft rice man’s self-cultivation (Completed)
The whole world is reborn (Completed)
I want to survive on a desert island (Completed)
The stallion male who has seized the opportunity (Completed)
The perverted self-salvation (Completed)
The spring of the loafer (Completed)
The misplaced life (Completed)
The miser career (Completed)
The ghost is out of feeling (Completed)
The Queen’s favorite husband (Completed)
The vicious girl with her godfather (Completed)
I want to be a good person (Completed)
I does not tear up the family (Completed)
The perverted common plant (Completed)
The Mary Sue’s men (Completed)
Every time I was reborn, someone wants to kill me (Completed)
The old people’s counterattack path (Completed)
The global evolution (Completed)
When I became a net red (Completed)
For you, good person (Completed)
His heart had white moonlight (Completed)

- Description from Novelupdates

Leon, a man who tragically died of exhaustion due to his sister's otome game, unexpectedly finds himself reincarnated as a young aristocrat named Leon Bartfort. However, he soon realizes that he is not alone in this body. Another mysterious entity already resides there, its voice echoing in his mind.Who is this second consciousness? Is it a friend, an enemy, or something far more sinister? Will they be able to come to an agreement to share control over the body, or will a fierce struggle for dominance ensue? Or perhaps their interactions will lead to unforeseen consequences?Intrigued? Then start reading!