Martial King's Retired Life - Chapter 14Book 15:

This is a world of swords and magic. Here, sorcerers and knights are well established, while alchemists and forge smiths are revered by the Empire. Mas transmigrated from Earth to this world and became an apprentice alchemist. This was a very noble status, a brilliant alchemist could command the respect of any major city. Mas was also proud of his own position. But he didn’t expect that his teacher was actually a huge fraudster, who used subpar alchemy products to trick the Royal Capital.

When they came knocking on the door fuming with killing intent, Mas’s teacher Wosk had already run away. While Mas, who was his student, was left behind to deal with this mess. If Mas was unable to hand up alchemy products that are powerful enough, he would be burnt alive by the people of the Great Empire. Just then, he finally awakened the God-tier Alchemist System and received the Creator’s Alchemy Station. On this station, any monster could be created. [Obsidian Gargoyle], [Lightning Naga], [Iron Golem], [Granite Golem], [Puppet Dragon], [Laval Titan]...... One after another legendary alchemy creatures were born in the hands of Mas, and he gradually gained the title of the God of Alchemy!

Humanity was on the brink of destruction. Muyoung, an assassin from the Forest of Death, fell to his knees. There were corpses all around him. For years, he had worked for the Forest of Death and had finally been able to eradicate them. Now, he, himself, was about to die. He closed his eyes as he felt his heart stop beating.

Full NTR*[Warning: This story is strictly 18+ and contains extreme NTR, explicit sex, mind-breaking corruption, and brutal violence. It is not for the faint of heart or those seeking a heroic journey. This is a tale of domination, destruction, and absolute fear. Only mature audiences who can handle dark, merciless storytelling should proceed. Read at your own risk.]***This story is a dark and ruthless descent into a world where power, manipulation, and betrayal reign supreme. A tale of absolute dominance, it follows a cunning and brutal protagonist who uses seduction, deception, and raw strength to corrupt, control, and destroy. No one is safe—wives, saintesses, and proud heroines fall, their purity tainted, their loyalty shattered. Betrayal is inevitable, and those who stand in the way meet gruesome, indescribable ends.**Brutal violence as Jin leaves a trail of broken heroes, shattered empires, and subjugated goddesses in his wake.

The celestial celestial beings who lived for more than 100,000 years were born and reborn in a small monk in a human world.
His motto: “It’s not as good as a medicinal medicine for ten years of hard work.” “Even if you practice a copper-iron bone, it’s not enough for my soldier’s attack.”

- Description from Novelupdates