The Hero Who Returned From The War Has Changed.

Franz was summoned to a medieval fantasy world to save humanity from demons. Now, 4 years later, humanity is close to achieving its goal. Franz has become the strongest human on the continent, and his sword is aimed at the demon capital after a bloody war on the verge of ending. Or at least, that's what the aristocrats of the kingdom thought until everything turns upside down at the celebration party in the royal palace.