Zeref (ゼレフ Zerefu) is considered to be the strongest, most evil Mage of all time, who possesses extremely dangerous, and powerful Magic. He currently appears as a reclusive, self-hating youth who cannot control his powers.
Zeref is said to have been the darkest, most evil Mage in the history of the Magic World, mastering the Black Arts and creating many Demons, some of which still wreak havoc in the present.

In the modern era, Zeref seeks to isolate himself and is very calm, sincere, and conflicted.[10] He wishes to die to atone for all the sins he has committed, and may commit in the future. He shows concern for others when he warns them not to come near him, knowing that they would die if they did. He is also somewhat emotionally fragile, as when he realizes that Natsu is not ready to kill him yet, he breaks down in tears.[11] Zeref often kills with no prior incentive or knowledge

In spite of all this, Zeref is very vindictive, and will punish those who he believes to be evil. This was shown when he ruthlessly killed Hades, whom he thinks has committed a number of unforgivable sins.[13][14] As a result of his immortal life, Zeref has developed a misanthropic loathing for humanity and its repeated idiosyncrasies of hatred, evil, and conflict.[