Who is Zeref from fairy tail?

Answer 1

Zeref Dragneel is a legendary evil mage from centuries before the current timeline. He mastered black magic, and created the Books of Zeref, from which can be summoned the Etherius, often referred to as 'demons', biological weapons he created. At one point in his past, because of his research into the nature of life, magic and death, he was cursed with immortality. He conducted this research because of the death of his beloved younger brother, Natsu Dragneel. He eventually turned Natsu into a demon, 'Etherius Natsu Dragneel', known as E.N.D. Natsu was given to the dragon Igneel to raise, before being sent 400 years into the future through the original Eclipse Gate.

Parts of his backstory as presented in the manga, are later shown to be false. A character was shown to be possessed by him, however this was actually an illusion created by the mage Ultear. While it is said that Zeref was sealed away, and that the dark guild Grimoire Heart was collecting the 'keys' that were needed to revive him, Zeref himself confirmed they were mislead by a myth.

Zeref had simply withdrawn himself from the world, going into seclusion on Fairy Tail's holy island of Tenrou Island. He claimed he had become tired of his life of evil, and wished only to die. He said that he had 'learned the value of life', which had the side effect of letting his death magic powers run out of control, hence his need to hide. However Grimoire Heart's interference angered him. He said people like them make him forget the meaning of life, regaining his full powers.

In the 'Fairy Tail Zero' story we learn that he befriended Fairy Tail's founder Mavis in the past, and taught her some of her spells. Her usage of an incomplete form of the 'Law' spell caused her to be affected by his curse of immortality. After she accidentally caused the death of 'Rita', Makarov's mother, she too withdrew herself from others, to avoid doing the same. She met with Zeref, wondering if they could live together happily without the risk of harming each other. Unfortunately Zeref's curse was stronger, and put Mavis into a coma.

Later Zeref is revealed to be Emperor Spriggan, ruler of the mighty Alvarez Empire. He has declared war against Fairy Tail, with the ultimate goal of capturing 'Lumen Histoire', the crystal containing the body of Mavis in a form of magical stasis. This would grant him nearly unlimited power, enough power to defeat the dragon of the Apocalypse, Acnologia. Zeref fears the dragon, because he has the power to wipe out mankind. Zeref cannot die, so would then face being Acnologia's plaything for all time.

After Mavis was released from the crystal, Zeref successfully extracted her powers and became 'white mage' Zeref. Even these extraordinary powers were not enough against Natsu though, and he was defeated in a climactic battle. As he lay there, recovering, Mavis approached him and the pair reconciled. With their feelings for each other now balanced, they successfully killed each other with their curses, bringing the story of Zeref to a close.

In the final issue, we see that he and Mavis have been reincarnated as new people with new names, fully mortal, who have a chance meeting and quickly become friends. That's the last we see of them.