After Natsu returns one year later, Fiore is invaded by the Alvarez Empire, a military nation ruled by Zeref, who intends to acquire Fairy Heart, a wellspring of infinite magic power housed within Mavis's equally cursed body preserved beneath Fairy Tail's guildhall. While battling Zeref, Natsu is informed of his own identity as both Zeref's younger brother and the true incarnation of E.N.D. (Etherious Natsu Dragneel), whom Zeref resurrected as a demon with the intention of being killed by him. When Natsu fails to do so, Zeref absorbs Fairy Heart from Mavis in a bid to rewrite the present timeline with one where he might prevent his own curse and Acnologia's rise to power. After Natsu defeats Zeref to stop the drastic changes to history his actions would create, Mavis lifts her and Zeref's curse by reciprocating his love, which kills them both.