Star Odyssey - Chapter 5: Cultivation

In the past, the giants of the heavens and the gods were destroyed after the reincarnation of the world! Cruel curse, eternal hatred, Tan Yun is determined to never sink again! For the sake of loved ones and relatives, from now on, step on the corpse of the enemy step by step to surpass the peak! Defying the sky, killing all worlds, I am the only one!

- Description from novelbuddy

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

A dangerous neon-lit city in a shattered post-war world.

The wilderness outside the city was wild and uncontrolled, the superhuman roamed beneath the cover of the night’s rain, xenomorphs prowled the streets.

Oligarchic company, extraordinary program, prosthetic limbs, spiritual network, street gangs.

Gu He only desire after transmigrating was to become a salted fish. But even if you wanted to, you couldn’t.

- Description from Novelupdates

Cairn is a prince who is already tired of ruling. Faced with an imminent coronation and an overbearing father, he wants nothing more than to drown his responsibilities in cheap liquor and poor decisions. With the help of his sister, he hatches a plan to escape the clutches of the throne once and for all. It all goes terribly wrong, and Cairn finds his priorities shifting in the face of unimaginable tragedy. The change of heart comes too late, however, and Cairn dies. He reawakens to find himself transported ten years in the past. He immediately begins to plan for the future, only to discover his killer has somehow followed him. To succeed, Cairn must unite the kingdom and discover the motivation of his killer, using as many tries as it takes. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++I exhausted pretty much every time loop story ever written and decided to write my own. You'll see a few similarities here between this story and some existing stories, at least initially. There's a lot of inspiration drawn from both MoL and Re:Zero, though in terms of pathos and darkness, this story leans more towards the latter. Be warned, it is something of a slow burn. The main character will grow and become powerful, but a theme of this story is that power comes slowly and often at great cost.