Naofumi Iwatani and his crew are in a rush to prepare for the impending Wave, but their plans are disrupted when bat familiars launch an attack on Lurolona Village, forcing them to delay the timer. The Four Cardinal Heroes team up with Queen Mirelia Q Melromarc to tackle this unexpected threat, which she suspects is caused by the reawakening of the dangerous Spirit Tortoise. They come up with a strategy to eliminate the creature, but only the Shield Hero, who is under a curse, is willing to lend his aid among the group of heroes.