The Misfit Of Demon King Academy (Light Novel): Volume 1 Ending Explained?

[YOU HAVE TRANSMIGRATED INTO A VILLAINESS FATED TO DIE.] I was supposed to obsess over the Alpha King, scheme against the heroine, and meet my end at the execution block. Instead, I rewrote the story. I chose Pierre Ashbourne—the neglected second male lead I once pitied as a reader—and spent three years helping him rebuild his dying pack, believing I had finally changed my fate. Then he abandoned me at our mating ceremony for his first love, the heroine. Now, the system has given me only one way home, restore the original ending by pushing the heroine back into the arms of the ruthless Alpha King, Hades. But the more I try to complete the story, the more these leads are getting out of character! What should I do?

A 25 years old boy named John is suddenly shot by his friend, which results in his death, but is reincarnated again as the new Demon King. Unfortunately, he agains dies in a battle. This time also he is reincarnated but as a human. Follow Vis' adventure as he gets revenge, becomes a demon and makes his own harem.

Serra is a normal senior high school student who works really hard every night and weekend to pay off her parents' debts from loan sharks. But when she couldn't keep up with payments anymore, she decided to end her life. Surprisingly, she woke up in a different light-- in another world. What's more shocking was when she is addressed by one of the people as the demon king's bride.

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.

A new sparks ignites Alanna's boring life when she gets unceremoniously kidnapped and taken to the underworld where she meets Zeron, a demon who is the king of the ice witches. Alanna thinks she has heard it all until she discovers that the king has been terminally ill for centuries and is dangerously controlled by his darkness, as a result of a curse that had been placed on him as a child. Furthermore, Alanna finds out that she is the king's cure and in order for the king to be free from the curse, she has to bond with him in every way, including marriage. Having nothing to lose, she agrees to help the king. Soon, she's falling in love with him. But will her innocent love be enough to save him? Will her passion remain unrequited, or will she finally succeed in breaking the icy walls surrounding the demon king's cold heart?

Arianna had not planned on using magic to summon anything, she just wanted to get out of an arranged marriage. She was told of the ancient magic of summoning a guardian but instead she had summoned a demon—the demon king himself. But what would he ask in return for his loyalty to this princess?