Loptyr (ロプトウス Roputousu, Loptous in the Japanese version) is a Dark Magic tome from Fire Emblem: Genealogy of the Holy War. The personal tome of Julius, the final boss of the game, Loptyr is a vile and potent spell that allows the Dark Dragon Lord Loptyr to possess its user. This spell possesses the unique effect of halving the attack power of enemy units before defenses are applied. This effect may only be nullified with the aid of the Book of Naga.