One Piece: Unreal Adventure - Chapter 103: I think we broke him, guys.

“Darling, I love you…” He was the heir to the consortium and she had just divorced. The day she was divorced, she was kidnapped and forced to be the doctor in charge of his case. To add insult to injury, this man would sleepwalk to her bed every two to three days… another headache!

There was a time where I was summoned to a different world. I spent more than a year as a Priestess from a different world. I fulfilled my role and decided to return to my original world. Before leaving, I confessed my feelings to my escort knight. And from there I was heartbroken. After returning to the original world for a year and half, I was summoned again. What? Apparently this time, nobody summoned me. I was sent out to a great extent and have a lost love. I cannot face anyone now! No one knows that I was a former Priestess and I can only quickly return to my original world. Even so, it does not seem to work out very well…

In a world where dungeons loom like dark secrets and monsters stalk the land, Rem’s awakening shattered the status quo. A surge of raw power flooded his veins as the Monster Monarch System bound itself to him, unlocking a terrifying potential.Each heartbeat echoed with the promise of countless souls waiting to be absorbed—skills, abilities, and monstrous strength ready to be claimed.Fuelled by an insatiable thirst for power, Rem set out on a deadly quest, driven by one singular goal: to rise above the chaos and stand at the pinnacle of the world. With nothing but the deadly abilities granted by the System, and a burning will to crush any who dared stand in his way, he carved his path through savage lands and ruthless mages.The hunt for strength never ends. The battle for supremacy has only just begun. Rem’s eyes are set on the throne of the Monarchs, and the Monster Monarch System will ensure nothing stands between him and his destiny.The grind was eternal...

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!