Sins of the Spriggan (Fairy Tail/Nanatsu no Taizai)

"Six months after Mavis' death and returned to isolation from humanity once more, Zeref encountered Meliodas who would soon lead him to become the member of the Seven Deadly Sins and help him heal and recover from the curse that is still inflicted upon him in Britannia. Now ten years later, Zeref now leads the Alvarez Empire for the war against the Holy Knights and liberate the kingdom of Liones to repay the debt he owed."