Season 6

This season has 39 episodes containing the "Tartaros" (冥府の門タルタロス編, Tarutarosu-hen) arc, which adapts material from the rest of the manga's 40th volume to the middle of the 49th volume, depicting Fairy Tail's battle with a dark guild of Zeref's demons who aim to resurrect E.N.D., their master and Zeref's ultimate creation.