Magika no Kenshi to Shoukan Maou - 1.1.3 — The Swordsman in Magic Division

Yo, Hi! I’m Frank, I made a deal with a demon to pay me some money for receiving a guest for a few days every week.
I had no idea about what I have done.
On May 1st, Conan ‘the God of Death’ came to my house. I was forced to let him in and we get involved in a criminal case.
On May 8th, Bruce Wayne ‘Batman’ came to me. I was forced to follow him to fight crime.
On May 16th, Hannibal Lecter, The Silence of the Lambs, came to my home. I can only say that I really can’t stand my guests.

- Description from Novelupdates

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!

Lin Xinyan was set up a one-night stand trade with a stranger man to get the medical treatment fee to save her mother. That night took her virginity and got her pregnant. Lin Xinyan never touched her husband-Zong Jinhao, until one day she found out her crippled husband was involved with another woman. The woman met her and recognized that Lin Xinyan was the one that she set up for that one-night stand. When she knew Lin Xinyan was pregnant with Zong Jinhao's child, she tried to kill her and her baby with every means she could. But Lin Xinyan didn't know that the man who slept with her that night was her husband, nor did Zong Jinhao know the baby was his, until one day...

This is a world where humans, demons and mysterious beasts coexist. Humans cultivate mysterious qi. Demons cultivate corporeal bodies. Mysterious beasts cultivate soul perception. A legend says that in the middle of an endless rainforest, there are extremely powerful existences; they are called demon kings. Some demon kings have a tyrannical corporeal body, some are experts in illusions. Some demon kings are proficient in magic, some can even move mountains. Some demon kings are able to sense things thousands of miles away. These demon kings rarely appear in the human world. Even if they emerge in the human world, they would reincarnate in human form; assimilating with mankind while seeking to breakthrough realms…….