Fire Emblem Three Houses - Paralogue: The Sleeping Sand Legend

The professor found Claude reading in the library; it turns out he was doing research on the Four Saints. One Saint that caught his interest is Saint Macuil who was a blacksmith who played a significant role in the Battle of the Tailtean Plans and lost his life there... or so it said, rumor has it that Macuil survived the battle and left Fodlan after the war. Claude also heard of a rumor of a giant beast guarding sacred weapons in the Sreng Region and deduced it belonged to the Saint himself. This piqued Claude's interest in going there, defeat the beast and grab the sacred weapons to win the war.