The Godsfall Chronicles - Book 7, Chapter 20 - Falling Short?

Sam Sanderson is envied by many for his job, however he himself didn't seem to like it much.

Due to his expertise in nanotechnology he was tasked with monitoring the state the Valkyries, humanity's strongest weapons who all just happen to be made into gorgeous females.

Forbidden from even touching any of them, Sam spends his days in agony watching flowers he couldn't hope to touch. However one day all of that seemed to change.

A supreme expert in the Immortal World had died, and a strand of his soul returned to its original body on Earth. Tang Xiu discovered with amazement that ten thousand years passed in the Immortal World, yet only a single year passed on Earth.

Ruthlessly betrayed by his lover and trusted friends, Tang Xiu found that his soul went back to his previous body on Earth, and, despite he spent 10,000 years in the Immortal World, just a year has passed on Earth and many things have changed. Having an unsurpassed knowledge, Tang Xiu will protect his loved ones and go back to the Immortal World to take his revenge.

- Description from Novelupdates

[Regressed successfully!]Zick lifted his eyelids, revealing two dull eyes. A grand room filled with medical appliances was reflected on his pupil.The piercing pain originating from the abdomen made Zick slowly accept the reality.He had returned 10 years back in the past!The very moment from when Zick began to lose everything.[Destiny system has been activated. Get closer to people with strong destiny and strengthen your own destiny!][Sub-function: shall be unlocked soon!]After taking a look at the interface, Zick closed his eyes.“First…I should repay that chick for this wonderful gift.” Zick looked at the bandages on his waist.......{Additional tags: Age regression, Evil protagonist, cold female leads, Academy, evil organizations, conquering, war.}

This is the tale of Arin, a once kind-hearted and gentle child, now a man hardened by the cruelty of society and the brutal trials of life—a man transformed into a ruthless criminal, devoid of mercy. As his world was collapsing, fate transported him to a new realm. This world, more vicious and savage than his own, was steeped in magic and dark mysteries.Ironically, it was in this fearsome world that Arin, now an undead being, began to rediscover his lost humanity. Through battles and bloodshed, amidst the clash of sorcery and steel, he started to reclaim the compassion he once hated. This is not just a story of survival but a saga of transformation. Follow Arin’s journey as he rises to power, determined to become the ruler of this harsh world. In a twist of fate, he now seeks to save the very humanity he once wanted to destroy.