RE: Monarch - Chapter 158: Whitefall XV

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

When gods gather, lightning will strike and the earth will move. Immortals! Which of the numerous way to immortality should one follow? Immortals are hard to seek, but why should immortals hide? Heaven has no mercy, but humans have emotions, and these emotions hinder the road to longevity!

Train the inner self to stay calm, train the external body to be resistant, then cross the three continents and four seas alone, and fight valiantly with demons and devils! With the heavenly baton in hand, raid the devils and demons without any resistance! Take one step to cross nine stars and chase the sword in the dreams! Traverse a thousand li of river and mountains in a single day! The exceptional beings do not mix with the ordinary! Within the universe, where can one find an obstacle! Moving like a dragon, with talent like a phoenix! The heavenly Daos and stars will guide one’s way!

- Description from Novelupdates

That lonesome night as he lays dying in the hospital, fearing of death and desiring the taste of life, his mind became unprecedentedly complex with mixed emotions.

— Doing good deeds brings blessings.— If actions meet societal standards, user ‘Jeong Da-on’ will have their restrictions reduced.Blessings for doing good deeds? Even if I was the Demon Lord in my previous life?It’s been 19 years since I ended my tumultuous life as the Demon Lord and reincarnated on modern Earth.I was caught by the system and forcibly turned into a Hunter. And now I have to do good deeds to regain my original abilities?“Hmm… Beating bad guys to death counts as a good deed, right?”That doesn’t sound too bad.Modern society is the perfect place for a demon to thrive, after all.