Blasphemy Wizard by Deceit World - Chapter 9: Ancient God Fire Lamp

An ordinary student, a wretched peeper, a cowardly teenager with a kind heart. In a terrorist attack, he inherited the knowledge of countless elites, embarked on a path of God Jagged Tu…

He is an artist!

He is a mathematician!

He is a psychology Doctor!

He is a master of fighting!

In fact, he is a man

Taken off raw site:

A wretched, dirty young man is working during the summer when he was caught up in a mysterious explosion. After that explosion, the young man is then left with the memories and knowledge of dozens of the world’s experts.

He has changed, his heart has become cold, iron-blooded. He became a killing machine, his mind turned mechanical, calculative. Everything goes according to his plans and calculations!

In this magical, slaughterous world, a door is opened for him…

- Description from Novelupdates

Kay didn't have the best life. Most of it was fairly standard, but his past was marred by a tragedy that changed his entire world. Years later he had managed to mostly rebuild his life, and had started making something of himself.

And then he woke up in a different world. A world of fantasy and [Classes], a world much more dangerous than the one he'd been born in.

The new world he's been dumped into doesn't hold anyone's hand. Even with the bonuses that being an Outworlder brings won't keep him perfectly safe. One mistake could kill him in an instant.

But maybe, with a little bit of help, he could start over once more, and start to make something of himself again. And maybe, just maybe, that something he makes himself into could be amazing. And bloody.

******

As I'm leaning right now there probably will be sexual content later on, but I might change my mind later. There definitely will be death, gore, violence, and blood. Lots and lots of blood.

I changed my mind. No adult stuff in this story.

Kusumi Chiharu gets a message one day that he has been selected as a Monster Tamer, and he is prompted to select his first partner. He thinks little of the message until he receives a giant package the following day. He assumes it’s the porn books he ordered, but the huge box ends up containing the unconscious body of a near-naked girl! She’s a ghoul named Zonmi, who intends to fight beside him as his partner.

However, it turns out that other hot girls at his mostly-male high school are also magical entities, and Zonmi may not be the only one who wants to fight by his side!

On that fateful day, a voice in the sky told everyone on Earth that the world they called home has just been part of some sort of simulation.