Superstar From Age 0 - Chapter 659:

Pei Jin is a black bellied prince. To outsiders he is a kind gentleman and always calm.

This novel is also known as Only I Level Up

10 years ago, after “the Gate” that connected the real world with the monster world opened, some of the ordinary, everyday people received the power to hunt monsters within the Gate. They are known as “Hunters”.

However, not all Hunters are powerful. My name is Sung Jin-Woo, an E-rank Hunter. I’m someone who has to risk his life in the lowliest of catacombs, the “World’s Weakest”.

Having no skills whatsoever to display, I barely earned the required money by fighting in low-leveled catacombs… at least until I found a hidden catacomb with the hardest difficulty within the D-rank catacombs!

In the end, as I was accepting death, I suddenly received a strange power, a quest log that only I could see, a secret to leveling up that only I know about! If I trained in accordance with my quests and hunted monsters, my level would rise.

Changing from the weakest Hunter to the strongest S-rank Hunter!

- Description from Novelupdates

Baek Ain is your typical lazy guy.

He graduated from university at age 22 with a random degree he chose out of boredom and stayed single because fate decided so until that event happened.

“What? Where Am I??”

After a horrible incident, Ain transmigrated to another world. Or precisely to be a villainous and mobs character.

He died countless times because of the world's protagonists, gathering hatred toward them.

“What the fuck! What do you mean I stole your wife? I've been single since coming into this world!!”

“Hero, please save this world.” A goddess is begging me to save her world from the Demon Lord.

“Wait... Begone thot! That Demon King is my younger sister from 69th Transmigration.”

“How dare you!”

A beautiful heroine is hugging me from behind, wishing to accept her feelings.

“Shoo, Heroine! I don't need useless baggage with me. Side characters are better than you!”

And so, Ain's journey began to end this shitty transmigration cycle.

On modern-day Earth, An Lin seems to have been abandoned by God.
When his father suddenly disappears, An Lin is left with his father’s immense debt, putting his life at risk.
After being forced to a rooftop by his pursuing creditors, An Lin is unexpectedly swept off his feet and brought to the ground safely.

After learning that he was saved by an Immortal, An Lin is gifted, seemingly out of pure generosity, the ‘God Of War System,’ and a pass to a new realm.
Follow An Lin as he experiences a whole new world of legends, meets many new friends, acquires legendary weapons and tools, and starts on his path of becoming a powerful cultivator. There is never a dull time in An Lin’s new life with his ‘great’ new system!

- Description from Novelupdates