The Legend of Heroes: Trails of Cold Steel II

The sequel begins a month after the end of the first title, with Rean having escaped with Valimar. He makes it to his hometown of Yumir where princess Alfin also escaped to, but she is kidnapped along with Rean's sister Elise. The rest of class VII has scattered over the country and he goes around gathering them and other Thors students, and after being given the airship Courageous by Olivier uses Valimar to help civilians and look for Alfin and Elise. The coup turns out to have been a plot by the leader of the Noble Alliance, lord Cheyenne, a descendant of the false emperor who had been defeated by emperor Dreichers, ancestor to the current imperial family, to gain power, and the Witch of the Abyss Vita, third apostle of Ouroboros, had been cooperating with him to fulfil the Illusion Flame project by making the Blaze Demon Castle appear and have the two knight-gods, Valimar and Ordine duel there. When Ordine loses, however, Cheyenne awakens the red knight-god Testarossa and thus the End of Vermillion, a legendary demon-god armed with a thousand weapons.

Source: Wikipedia, "The Legend of Heroes: Trails of Cold Steel", available under the CC-BY-SA License.