How Does Upper Demon 1 Challenge Human Protagonists In Fiction?

A new world with nearly unlimited possibilities. A system, classes, magic, skills and monsters. Sounds exciting? But for Jin it didn't go quite as he expected nor was there a princess or a Goddess to welcome him to this new world, his only hope was the system he received. Left alone in the darkness, How will he survive when he wasn't human in the first place?

He died killing the Demon King. He woke up sixty years too early. Now the monster is a young man. And he is running out of reasons to stay away. --- Lysan Dusk was the hero who saved humanity. He killed the Demon King, ended the war, and delivered the world from suffering, and his reward was betrayal. He wakes up in a young student's body in a dormitory room of a magical academy, and the calender shows that the date sixty years before he was born. The world outside hasn't broken yet. The war hasn't happened. Lysan's plan is to keep it that way by staying completely out of it. Fail his combat exams, spend whatever borrowed time he has left, living a quiet life, where nothing requires him to be a hero. The man who will become the Demon King, the most feared monster in history is still young and beautiful, with pale grey eyes that find Lysan across every crowded room like he is the only person worth seeing. Lysan knows what those eyes will become. He has looked into them across battlefields, spent a lifetime seeing them in nightmares. He never expected it to feel like this up close. Roman is everything Lysan was warned about — magnetic, dangerous, impossible to ignore. Everyone except Lysan, refuses to be charmed, refuses to feel anything at all. But now, he is failing spectacularly at them because Roman keeps finding him. Keeps watching him and making Lysan's carefully rebuilt walls feel like paper. Lysan knows the ending. But for the first time in two lifetimes, he is wondering if the ending can change. If the monster can be loved instead of killed. If staying is braver than running.

In a world with machines and angels, the main character has to become the strongest to avoid getting killed and discarded.

My best friend and I were pulled together into a steamy dark-fantasy romance novel, where we became the Demon King's newest sacrificial consorts. As someone who had actually read the original book, Elodie went pale. After all, this was the raunchiest, most over-the-top novel the two of us had ever read. She grabbed my hand, trembling. "Camille, if I'd known, I never would have wished on my birthday a few days ago to die of pleasure in some gorgeous man's bed. Now it looks like that dream is actually coming true—except the price is my life..." What she didn't notice was the drool sliding down the corner of my mouth. As the highest-ranking succubus, I'd spent years disguised as a human in the modern world, starved of nourishment and all but withering away. Now I'd crossed into a world with no morals and no rules to hold me back. It suited me perfectly. So the moment I laid eyes on the Demon King in front of me—blisteringly hot to the touch and devastatingly handsome—I didn't hesitate for a second. I lunged forward and sank my mouth into his veined, muscled chest. "Sorry, Elodie. A blessing like this, I'm claiming for myself!"

He is a demon but also he is a fallen angel. After the war with seraph, he lost his love and became a demon with a broken heart, until he met a girl.

"The trials ahead to prove my worth? I'll crush them !! Enemies? I'll slaughter them!! " Waking up in a new body and a new world after dying on Earth, Tsarayu embarks on a new journey in a world filled with gods and demons. A world where myriad of life forms exist and humans can cultivate and become immortals. Watch him rise to prominence with a supreme inheritance and his hard work as he slaughtered everyone who stood in his path. Watch His journey as he became known in the Universe as the Demon God, the ruler of death forcing the heavens to bow before him. Known as the second inheritor, what happened to the first one? Who does this legacy belongs to? What secrets is the universe hiding?