The name of Darien Kidd's zanpakuto. Translated into English from its Latin words, it means "It is folly to die for one's country." Not much is known about this zanpakuto except for what its spirit looks like, that it is a double zanpakuto, what one form of its shikai looks like (it has others, but no one other than the captain, and maybe one or two of his family has seen them), and what its bankai looks like and the name of the bankai. This zanpakuto is usually activated when Captain Kidd calls out "Reveal yourself, Dulce et Decorum est!!!"
The zanpakuto's spirit is a small female dog with a personality to match that of Darien Kidd's: ill-tempered and feisty, yet very loyal.