Toaru Majutsu no Index SS - Volume 2, Chapter 14: The Dance between Gatekeeper and Intruder. The Third Friday of September.

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!

Orion was on his way back home from work.He was hurrying back home to take a nap while planning how he would spend his weekend as well, but while he was lost in thought, a truck suddenly appeared out of nowhere and the last thing he remembered was the truck barreling towards him before everything around him turned dark.However to his surprise, he didn’t feel any pain after having the accident. In fact, he couldn’t see anything.Everything around him seemed dark but when he opened his mouth to speak, he heard the gurgling sounds of a baby.Noticing that the one sounding like a baby was him, Orion tried to open his eyes to know exactly where he was, but when he did, the first thing his eyes fell upon was a stunning beautiful elf, holding him with the most tenderest of care.Not only was she his mother, she was also a queen as well and she had a beautiful sister who adored him just as much as his mother.Aside from this, Orion also noticed he had received a system which allowed him to grow and evolve faster than a normal High Elf but after finding out the huge role his mother played in eradicating the war between all races, Orion vowed to live a happy and fulfilling life with his mother, aunt and a few others he cared a lot about.

Humanity was living peacefully on Earth for millions and millions of years until the day unknown monsters from beyond space invaded them.

When humans were about to disappear, some people with abilities came out to the light and shared their knowledge and powers with the world, and together, they managed to push back the invaders during a terrible war that had lasted for years.

This war had created many orphans, and among them, Kye had lost everything, even his parents. And the only thing he received from their death was a pale-looking necklace.

However, once the necklace finally activated, a system was given to him, and his life changed completely.

The system gave him quests to do, and Kye complied. He was getting stronger every time he achieved them, until the day it gave him a weird quest.

[You have one day to kill the one who had sinned. If you do not kill, you will die.]