Zeref Dragneel

Zeref (ゼレフ, Zerefu) is considered the strongest and most malignant Mage in history, who possesses incredibly deadly and powerful magic. He currently appears as a self-hating, reclusive youth who cannot control his power.

History
During an undisclosed era, Zeref witnessed the deaths of individuals in a great war, having also been cursed at some point he began peculating others souls nearby with lack of intentions.

It is stated he is from ancient times and presumably weilds unfathomable power from which even the most timbultuous of mages quiver at. The mage Ultear Milkovich comments on a legend of how he journeyed to an ancient land, mastered and assimilated Dark Magic and brought into existence tens uponr thousands of demonic forces which brought the world under disorder.