I Can Hear a Serial Killer's Voice in My Head - Chapter 41: The Fifth Case (6)

The life story of Gun Choi going towards being the best pitcher in the baseball Major League.

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

Amidst a disaster, an orphan contracts a sickness.

I opened my eyes to find myself in another world. For some odd reason, I ended up as a sword. Before my eyes laid a plain full of magic beasts, and so, I launched my body and flew in search of a partner, a wielder (females only).