10 nen goshi no HikiNiito o Yamete Gaishutsushitara Jitaku goto Isekai ni Ten'ishiteta - Volume 12, Chapter 5 Yuuji, entering the perilous pass on the fifth day of their trip

Waking in a strange yet familiar room the main character now will rise to the top of one most dangerous worlds of fiction with his new cheat.

Shen Yuan, a normal human who was living his life peacefully on earth died mysteriously, only to get reincarnated into the world of cultivation with an unknown bloodline so powerful that it even surpassed his chest system....“Hmm, looks like becoming an alchemist might be good. System, purchase the Alchemy knowledge.”[Ding!][Congratulations Host, for acquiring Heaven Refining Alchemy Sutra.]...Follow to see the journey of how Shen Yuan creates the strongest harem since the Primordial times to journey the three thousand world.

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

“I shouldn't have used illegal downloads in the first place.”

Ian woke up in the middle of a strange swamp as his own terrible character.

In a dark era on the verge of destruction, the hopeless character struggles to safely return to reality.