Nerva Julius Caluades

Nerva is arrogant and intensely conscious of his imperial birth. He looks down on other countries and favors the expansion of Reim's power, while also displaying contempt toward the Fanalis Corps despite their importance to the empire's military.

His confidence is greater in political matters than in actual use of his Metal Vessel. During the Magnostadt battle he is visibly uncomfortable when expected to join experienced Dungeon Capturers in Full Djinn Equip, because he has not mastered that level of Shax's power.

Nerva's dissatisfaction also comes from Reim's political structure. Being the emperor's son does not guarantee succession, and his desire for hereditary authority becomes increasingly important to his later actions.

Nerva conquered the 44th Dungeon and obtained Shax. His Metal Vessel is a sword.

Very little is established about Shax's specific magical properties. More importantly, Nerva has not mastered Full Djinn Equip during the Magnostadt conflict. This separates him from veteran Reim Dungeon Capturers such as Muu Alexius and Ignatius Alexius, who can bring their Djinn powers fully into battle.

Nerva nevertheless remains a Metal Vessel user, giving him access to power far beyond that of an ordinary soldier.

Nerva appears among Reim's leadership during preparations for war against Magnostadt. He witnesses Aladdin's demonstration of his power and looks to Scheherazade for confirmation that the young magician truly is a Magi.

During the battle against the Medium, Nerva accompanies Reim's Dungeon Capturers but remains behind when others perform Full Djinn Equip. His inability to do the same emphasizes that simply conquering a Dungeon does not guarantee mastery of a Djinn.

Years after the establishment of the International Alliance, Nerva rejects the new order and disappears with Shax. He becomes associated with terrorist attacks and is described as one of the world's most wanted Metal Vessel users. His actions are connected to his desire to overturn Reim's non-hereditary political system and establish himself as a prince in a stronger dynastic sense.

Scheherazade is the Magi who selected Nerva as one of her King Vessels. He treats her respectfully despite his arrogance toward many others.

Muu Alexius is another of Scheherazade's King Vessels and serves Reim alongside Nerva. Nerva looks down on the Fanalis Corps that Muu commands.

Ignatius Alexius is another Reim Dungeon Capturer and participates with Nerva in the empire's military leadership during the Magnostadt campaign.

Aladdin attracts Nerva's attention when his abilities reveal that he is a genuine Magi.

Yunan later identifies Nerva as one of the Metal Vessel users who has rejected the International Alliance and reports rumors concerning his attacks.