MTL - Problematic Sister Fell In Love With Me - Chapter 5 Am I an accomplice?

When a glowing portal yanks Leo from his struggling existence, he is saved by a mysterious system which gifts him new chance to break free from his side character experienceRebuilding an abandoned guild to honor his family’s legacy, Leo finds himself under the evil eyes of monsters, both from humanity and the gates he ventures intoin short : overpowered necromancer building a guild.

Waking in a strange yet familiar room the main character now will rise to the top of one most dangerous worlds of fiction with his new cheat.

Killed by a Sage Emperor and reborn as his 13 year old self, Nie Li was given a second chance at life. A second chance to change everything and save his loved ones and his beloved city. He shall once again battle with the Sage Emperor to avenge his death and those of his beloved . With the vast knowledge of hundred years of life he accumulated in his previous life, wielding the strongest demon spirits, he shall reach the pinnacle of Martial Arts.

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