Advent of the Archmage - Chapter 641 - Sovereign of Light?

There’s an ancient saying in Great Ruins, ‘Don’t go outside when it’s dark.’

Suddenly a high school student Subaru Natsuki has been summoned to another world on the way back from the convenience store. With the biggest crisis of his life being summoned to another world and no sign of the one who summoned him things become worse when he is attacked.

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

I was sixteen when the gods abandoned me.The Blessing Ritual was supposed to grant me power, a divine gift to carve my future. Instead, I received nothing. No abilities. No hope. Just another nameless soul left to rot in a world ruled by strength.Fine. If the gods wouldn’t bless me, I’d make my own power.For ten years, I clawed my way forward, experimenting with forces no human should touch. I pushed too far—and it killed me.Then I woke up.Sixteen again. Back at the Ritual. But this time, something changed.Time bends at my will. Blood moves when I command it.The gods still won’t acknowledge me, but it doesn’t matter. This world isn’t fair, and I’ve stopped playing by its rules. Faith and Chaos clash in my veins, and I will use them both.They wanted a Chosen Hero, someone to dance to their tune.Well, too bad for them—I’ll carve my own fate.