While Light was busy clearing the Abyss of monsters so that he had somewhere to build his new kingdom, his former Concord of the Tribes cohort, Naano, was slowly slipping deeper into despair. Despite being showered with riches and securing a top job in the Dwarf Kingdom's most distinguished smithy, the talented blacksmith felt the course of events was taking him further and further from his life's goal: to craft the ultimate legendary weapon. However, an encounter with a human merchant puts him on a new, much darker path to fulfilling his dream, and with his goal now in sight, Naano will stop at nothing to craft a legendary sword, even if it means spilling the blood of countless innocents. Meanwhile, Light's quest for revenge on Naano leads to him striking a deal with the ruler of the Dwarf Kingdom, King Dagan, but will aiding him to explore some vast, labyrinthine ruins replete with deadly traps and powerful guardians from which no one has returned prove to be an unwise undertaking?