Third season of Yuuki Yuuna wa Yuusha de Aru.

The wandering knight, Bedivere, reaches the end of his journey. The year is A.D. 1273 in Jerusalem. The Holy Land has been transformed into a massive desert, the people have been forced out of their homes, and three major powers wage war with each other in this wasteland. The Knights of the Round Table come together to protect the Holy City and their Lion King. With the whole of his kingdom summoned into a strange land, Ozymandias, the Sun-King, quietly plots against the tyranny of this bizarre realm. The mountain people, protectors of those who were stripped of their land, await their chance at rebellion. In order to fulfill his mission, Bedivere heads for the Holy City where the Lion King rules. There he meets humanity’s final Master, Ritsuka Fujimaru, who has come to Jerusalem, accompanied by his Demi-Servant, Mash Kyrielight, in their quest to restore human history. Bedivere joins with Fujimaru and his companions to undertake this quest.

In a city of the dead, long since ruined and far from human civilization, lives a single human child. His name is Will, and he's being raised by three undead: the hearty skeletal warrior, Blood; the graceful mummified priestess, Mary; and the crotchety spectral sorcerer, Gus. The three pour love into the boy, and teach him all they know. But one day, Will starts to wonder: "Who am I?" Will must unravel the mysteries of this faraway dead man's land, and unearth the secret pasts of the undead. He must learn the love and mercy of the good gods, and the bigotry and madness of the bad. And when he knows it all, the boy will take his first step on the path to becoming a Paladin. (Source: J-Novel Club)

In an alternate reality world that resembles Edo Period Japan, Luffy acts as a member of the police. This is made up of two adventures: in the first, Buggy makes trouble in the town; in the second, a mysterious girl named Vivi appears (aired after Episode 253). This special contains several cameos from characters throughout the entire series. A second pair of episodes were aired after episode 290, continuing this story, as part of the New Year's special.