After receiving a warning that Yunyun's hometown is in danger, Kazuma's party is relieved to discover it's only a joke...until it isn't. The Demon King's general has just arrived to obtain The Mage Killer, a weapon with world-ending power.
Facing possible annihilation by the Demon Emperor's demi-hum...
The time is UC 1926. The Imperial Army's 203rd Air Mage Batt...
The Demon Slayer Corps are drawn into the Infinity Castle, w...