As Ein delves deeper into Ishtarica's greatest secrets, he's suddenly reminded of the legend Professor Oz once shared with him. The prince tries to connect these puzzle pieces when he receives a troubling report from across the ocean—Heim is gearing up to invade its neighbors while Euro has been overrun by mysterious creatures known as chimeras.

Unable to let these heinous acts slide, Ein and the Ishtaricans quickly take action against Heim's devious machinations. But while doing so, the crown prince comes face-to-face with a shocking revelation regarding his most trusted confidants. Can Ein save the world and destroy the roaming chimeras, even with the deck so stacked against him? And more importantly, can he find the strength to stand on the front lines of a grisly war in order to protect his loved ones?