Kindan no kjóen (S01E13)

Rider and Waver make a trip into town, and stop in a bookstore along the way. There, Waver reads a biography on Rider's life and learns why he aimed to conquer the far east. Meanwhile, Caster and Ryuunosuke return to their destroyed base. A conversation with his Master leads Caster to an epiphany, and with insanity in his heart, the mad magician begins casting a certain spell... (Crunchyroll)