Black Bellied Belle: Demon Lord, Bite The Bait Please - Chapter 231.1 - Mysterious Intruder

In a world where kingdoms rise and fall, a seasoned player unexpectedly finds himself transmigrated into the very game he once mastered—Caldera. However, his new life as a ruler comes with a crushing twist: severe debuffs and harsh restrictions on his talents make survival nearly impossible. Against overwhelming odds, he fights tooth and nail to carve out a legacy. Despite his brilliance in strategy and marvels in combat, failure becomes his ultimate fate.

This is a story about the protagonist getting the system, going crazy in the biochemical apocalypse, producing aircraft and tanks, destroying zombies, saving good people and killing bad people.

- Description from novelbuddy

Riku Aoyama was just a broke, unlucky and starving college dropout waiting for his time and scraping by on instant noodles, and ended up as part-time buddy—until a mysterious vending machine offered him a deal: a system that lets him buy anything.Want a skills? Check.Looking for knowledge? Instantly downloaded.Legendary weapons? Delivered to his door.Authority, time, fate, even the affection of others? All up for sale—if he can pay the price.With the Infinite Wallet System, Riku’s once-pathetic life turns into a wild ride of action, opportunity, and temptation. From unlocking forbidden martial arts to building a harem of powerful women drawn to his rising charisma, Riku is determined to forge an empire, one purchase at a time.But every system has its cost. As he gains power, hidden forces begin to notice his ascent. Gods, demons, and beings beyond reality have started watching—and some want to claim the system for themselves.Action-packed, hilarious, and mature, this is the story of a man who can buy everything—except his own peace of mind.

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