From Thug to Idol: Transmigrating to a Survival Show - Chapter 9: Side Quest

The Immortal Path led to Longevity and Sovereign was heading in ease. When the Longevity was no longer in ease, all living beings were just prisoners. Conspiracy, internal strife, and the invasion of the others, all of it emerged together. 

In such a world, there was such a young man. He made his way upstream, stepping on blood, defying the emperor, destroying the various kings, and slaughtering his way through the hundred clans to form an Immortal Path towards the throne of Sovereign! The Immortal Path was endless, while the Sovereign was limited. He used his blood to forge his immortal legend.

- Description from Novelupdates

The Story of One Continent ~Allison and Wil and Lillia and Treize and Meg and Seron and Everyone Else~ is one final send-off for the long-running series of novels by Keiichi Sigsawa that includes Allison, Lillia and Treize, and Meg and Seron.

As this is a sequel that involves characters from all three series, you are advised to read all of Allison, Lillia and Treize, and Meg and Seron before diving in.

I was proposed to by the Final Boss.

Jeong Yoo-shin, 23 years old, was suddenly transported to another world.In this world, not only was it impossible to return home, but even survival was uncertain.Black-haired humans were called Barbarian and treated as northern savages.There was only one place where he could gain the strength to survive and find a way to return home: the Great Labyrinth.“I must become stronger to survive. And I will definitely go back.”This is the story of a black-haired human’s fierce struggle for survival in the labyrinth.