Versatile Mage: Start by Obtaining the Death Scythe

In a world filled with demons, humans are trembling under the demons' armies.
Faced with this hopeless world, with the Grim Reaper's scythe in hand, Tang Longhui vowed to kill all these demons.
The world of the future will eventually sing the name of the god of death.
PS: The male protagonist is a native, and will try his best to save the regrets of the original work...