Advent of the Three Calamities - Chapter 589: Source [1]

“It’s finally here,” said the man with the sword in an echoing whisper.

“The Tower of Choice, the last 100 floors!” the band of five exclaimed in unison.

Angelica came down from the altar with a dull look, seemingly annoying.

Then we looked around.

“I tell you once again, but you’ve had a lot of trouble in the meantime. I couldn’t have climbed to the 100th floor alone without you.”

Thud!

One by one, they fall to the floor.

Angelica’s dagger pierced my neck, and I felt a darkening in front of my eyes with a tumultuous rage. My awareness faded, from my senses, from everything else. After that, everything was eroded by profound darkness.

[The Demon King is Dead], a story in which the Demon King got immediately killed in the Prologue. I became the ‘Demon Prince’ of said novel.

…Help me.

lexander, a young billionaire, and some of his classmates died in a school bus accident. They had another chance to reincarnate in a fantasy universe. A world of Sword and Magic. However, while everyone got a wonderful gift, Alex got two guns. One is silver-colored while the other is black. He couldn't even use magic. Even when others made fun of him, and his stats were below average, Alex was still smiling as he believes in himself. With a fiery eye, he said: “On Earth, I was one of the richest, and in this New World, I shall be the strongest.” Together with the others, they were sent to the next world to begin again. This is the story of Alex with his two guns in another world, a fantasy world. The story of his struggles until he became the strongest. The tale of a journey towards the top.

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