A Hentai System in the World of Danmachi - Chapter 29 - 28 - Liliruca.

Humbra bleeds, devastated by an unrelenting race for survival against the Leirions—powerful monsters intoxicated by their bloodlust. Amidst this chaos, a young orphan, haunted by his brutal past, discovers he is the catalyst to a greater future—a future far darker than he could ever imagine.This is Leonard, a boy whose destiny entwines with ancient secrets, betrayals beyond reckoning, and a world-shattering rage.Humanity already struggles on the edge of the abyss. The light of hope has long been extinguished, ushering in the darkness and heralding echoes of lament... But from this despair, a new hope flickers: the Neumonds, wielders of powers that transcend life and death. Are they saviors... or harbingers of a final, devastating curse?Will Leonard save them all... or will his desire for vengeance end in a valiant death?

I wanted to rely on hard work and hard work to become stronger, but I found that lying down is more comfortable.

The point is, you can upgrade while lying down!

Why should I stand when I can lie down?

- Description from novelbuddy

I came from hell, looking for redemption! –“Revelation”
…………
What is redemption?
I think it should be a process in which a good person becomes bad and then becomes good again.
It’s like our clean birth, contaminated by the dust of one life, and then clean death.
Well, this is just a story. …

- Description from Uukanshu

A failed investor from 2017 got drunk and woke up in the 1980s. China is just opening up, and the economy is blooming. There is also the dissolution of the Soviet Union, the bursting of the Dot-com bubble and other financial crisis. He used his knowledge of the future and slowly build up his empire.

- Description from novelupdates