After Apocalypse, I Got Rich With Superpower - Chapter 66 - 64 Craftsmanship

To take a dragon's hoard is to challenge death.The greatest of the sea-drakes wakes, curled on his silver throne; but there is no silver. His hoard is stolen. He rises, screaming, and chases the thief to the ends of the world—only to be shot from the sky.But dragons do not die easy, and never one with such festering hatred. A dungeon core rises from his corpse.If he intends to survive so near the cove of pirates that slew his past self, he'll need to master his powers—and quickly. For these pirates are dragonslayers; they won't be felled by mere mushrooms or spiders.Beneath the lawless Calarata, the young dungeon core will have to fight to survive; and one day, he will return death to the man who killed him.

It was in the year 2800 of the Midgard calendar. Back then, there was a Overlord who once reigned supreme and had reached the very brink of subduing the world.

A side story series featuring the girls of Kyoukai Senjou no Horizon.