MTL - From the Head Pillar Tanjiro, Take Stock of the Wonderful Nicknames of Zongman - Chapter 568

In 2100 at the turn of the century the first full dive VMMORPG game 'Omega' was released

Char lived alone in the closed beta test of “Fantasy World” for thousands of years. He had already experienced 177 data wipes. In this span of time, he had already successfully charmed all of the NPC beauties, challenged all of the bosses single-handedly, gathered all of the divine weapons and used hundreds of methods to complete the online game as though it was a replayable console game. Just as he was losing the ability to differentiate whether he was a player or an NPC, the public beta started for “Fantasy World”. As such, a player who was even more terrifying than a boss was born.

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

This is a story of a man named Kim Sae-Jin, who one day, inexplicably wakes up as a Monster. Follow him and his perilous journey to get his life back as a Human, all the while growing even more versatile as a Monster in the process. This should be… complicated, somewhat.