Fire Emblem: Genealogy of the Holy War (Nintendo Cinematic Universe)

Fire Emblem: Genealogy of the Holy War is a Japanese anime film.

Summary
Two generations. One story.

Plot Elements

 * In the year Grann 757, barbarians from the kingdom of Isaach besiege Darna Castle, and Prince Kurth of Grannvale and his friend Lord Byron of Chalphy set out on a punitive expedition. When the southwestern kingdom of Verdane takes advantage of Grannvale's weakened state to invade, Byron's son Sigurd repels them and launches a counter-invasion.
 * During the campaign, Sigurd meets a mysterious girl named Deirdre. She is revealed to be of Naga blood, a long-lost member of the Grannvalian royal family, the House of Belhalla, and the descendant of the crusader with the power to defeat the evil dragon Loptous.
 * Sigurd and Deirdre fall in love and marry, and their son Seliph is born in Agustria. At this point, Dukes Lombard and Reptor conspire to seize the throne of Grannvale, murder Kurth, and frame Sigurd and his father for the crime.
 * Sigurd is forced into exile, while the archbishop Manfroy of the Loptr Church kidnaps Deirdre and erases her memories in order to use her to resurrect Loptous. His plan is to wed her to Lord Arvis of Velthomer — the two are, unbeknownst to them, half-siblings, and their union will produce a human vessel capable of hosting the consciousness of Loptous.
 * During their exile, Sigurd and his allies are forced to hide Seliph and the rest of their children from the forces of Arvis and the cult.
 * After a year in exile, Sigurd starts making his way back through Jugdral, killing the Dukes responsible for the false accusation.
 * Apparently exonerated, Sigurd returns to Grannvale, only to learn that Arvis has married Deirdre to become Grannvale's king. Arvis orders Sigurd's allies to be executed and personally murders Sigurd.
 * Over the next fifteen years, Grannvale expands to hold dominion over the whole of Jugdral, and Arvis styles himself the emperor of Grannvale. He and Deirdre have twin children: Julius, the scion of Loptous, and Julia, the scion of Naga.
 * Manfroy uses the Loptyr tome to corrupt Julius, turning him into Loptous's vessel, while Deirdre sacrifices herself to warp Julia away from Julius.
 * Julius overthrows his father and turns the Empire into a tyrannical regime. At this point, Seliph comes out of hiding to protect a nearby village, revealing his long-hidden existence to Grannvale.
 * Traveling across the lands of Jugdral, Seliph joins forces with the long-hidden children of Sigurd's companions, as well as Julia. Making his way through the countries of Jugdral, he gains support from the surviving powers, and gradually frees Grannvale's conquered territories.
 * Arvis is powerless to subvert his son's rule, and is killed in battle against Seliph. During the course of these battles, Julia is captured and Manfroy and Julius attempt to sacrifice her, as her powers could banish Loptous for good. Seliph manages to save her, and after defeating Manfroy and Julius in battle, Julia successfully banishes Loptous, finally ending his rule and allowing Jugdral to recover from the recent conflicts.
 * Seliph takes his rightful place on the throne as the emperor of Grannvale, and restores power to the surrounding countries with their respective heirs.