To Be a Power in the Shadows! - Chapter 141

Qin Tian accidentally transmigrated into a sickly body, a body with broken Dantian that was unable to practice Qigong, in another world. Fortunately, God had mercy on him by giving him a level up system. Useless? That was him in the past. Not worrying about practicing Qigong, he was now able to kill Monsters to level up. Easy! Level up when killing Monsters; level up when killing people. An unbeatable sovereign of the clan in the eyes of other people, but in his eyes, he is a glittering big BOSS.

With this level up system, he will no longer encounter any bottlenecks during a breakthrough in cultivation like other geniuses; all he needs to do was kill as many monsters, clan heads, sovereigns, world experts … to have a better life.

Dedicating his life on a road to become an expert.

- Description from Novelupdates

For the wine to be drunk on her wedding night to actually have been a cup of poison and for the one to poison her to be her husband, who would believe it?

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