I Alone Level-Up (Web Novel KR) - Chapter 174

The prosperity is about to come to an end, and the poor boy quietly rises.

Traveling across time and space, seek the leader of the world.

- Description from novelbuddy

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

Betrayed. Exiled. Murdered. Reborn.In the war-torn land of Glory, power is everything and Duke Merlin's bastard son has none. Cast out to a starving border town beside the cursed Devil Forest, Kaelor and his mother were meant to die quietly.But when assassins take her life and leave him bleeding in the mud, another soul awakens within him one from another world.And with it, something else awakens too...The Fusion System.A power that lets him fuse nearly anything.Fusing one starving soldier with a dead direwolf gave birth to a Dreadwolf Trooper.Fusing one hundred wild dogs produced the monstrous Cerberus.Fusing two crumbling forts created a living fortress bristling with autonomous ballistas.From broken men and dead beasts, Kael will forge an army the world cannot understand and a dominion no one will dare challenge.