BLOOD LEGACIES - Chapter 33: Invite Me In

He is a young man without a spirit root. It is believed that this denies him the chance at cultivation. However, a mysterious lady imparts a Supreme Demon Classic to him and from then on, he starts his path of cultivation.
He undergoes a total transformation to emerge as the most fearsome and powerful fiendish demon in his era, that even immortals and fiends are fearful of him, and saints are at his beck and call.
Mastering the Supreme Demon Classic is the turning point in his life. He is able to unleash his immense and divine power from within, illuminating the entire universe!

- Description from Novelupdates

Kim Jeongjin, an editor of a publishing company on the brink of closing due to bankruptcy, ends up transmigrating inside a fantasy novel as the incompetent youngest son of a wealthy family.

And here he thought that he should live a rich life in this life…

“Why was I given a high-level skill? Don’t even bother!”

The empire has turned into the land of the undead due to a spell gone wrong. God summoned heroes from countless worlds to purify the empire and plant new hope. Lee Shin Woo, an ordinary earthling, was also summoned. As an undead, that is.

I became the childhood friend of the protagonist in a novel. The childhood friend who died from taking drugs.