I'm Trapped Inside a Prince as the Most Powerful Entity - Chapter 5: Glimpse of Adam Power

As Orson read the novel written by the girlfriend who had left him, he gently remarked on how terrible the story was. But then, noticing a foul smell coming from the kitchen, he went to investigate. He realized there was some kind of gas leak. Already furious about being dumped, Orson became even angrier at the state of his kitchen, and in his rage, he hit the light switch with a powerful punch. Naturally, the explosion that followed killed him instantly, and Orson passed into the afterlife.After spending some time in limbo, he found himself reincarnated in an unfamiliar world. However, he quickly realized he had been reborn inside the cliché-filled novel written by his ex-girlfriend. As if that wasn’t enough, he had ended up in the body of Neonidas, a useless duke who was also the fiancé of the story's villainess.____There may be a bit too much swearing and slang in the first chapters, but it gets less afterwards.There will be no yuri, bl or ntr in Neonidas(MC) harem

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

I found a girl of unknown origin outside; she claims to be a time traveler from a post-apocalyptic era.Great calamity is imminent, with abominations spreading across the land, human civilization annihilated, and even the world itself shattering, all beyond redemption.As for myself,I am considering how to confine this beautiful girl, who has temporarily lost her powers, within my home.

Eighteen-year-old Trinity is unlike any other werewolf in her pack. For one, there were unusual circumstances surrounding her birth, for another, she is the only pack member to never shift into a wolf form. So now she doesn't quite belong anywhere. Not quite human and not quite wolf.