Yaqut

Yaqut displays a relaxed sense of humor around his comrades. When Lo'lo' accidentally sends Muu flying, Yaqut reacts by remarking that their captain has been sent flying again rather than treating the incident with alarm. He similarly smiles when Lo'lo frightens Nerva Julius Caluades.

His ambitions outside combat are unusually mundane. Supplementary material gives his dream as marrying or attaching himself to a wealthy noblewoman, while his preferred type is a mature woman. In battle, however, that relaxed demeanor disappears and he fights seriously as part of Reim's most dangerous close-combat unit.

As a Fanalis, Yaqut possesses physical abilities far beyond those of an ordinary human. His enhanced strength allows him to engage magicians and magically equipped soldiers directly, while his exceptional speed makes closing the distance against spellcasters much easier than it would be for conventional infantry.

He fights as part of the Fanalis Corps rather than as a Metal Vessel user. During the battle with Magnostadt's magicians, Yaqut and Razol withstand ordinary magical attacks well enough to continue advancing and attempt to reach the enemy barrier while avoiding concentrated fire.

Yaqut appears with the Fanalis Corps during Reim's preparations for war with Magnostadt. He accompanies Muu, Razol, Myron Alexius and Lo'lo as the empire deploys its elite Fanalis against the magician nation.

During the invasion, Yaqut and Razol fight together against Magnostadt's magicians. When several Fanalis are incapacitated after the defenders combine diverted water with electrical attacks, Muu temporarily leaves the fallen members in Yaqut and Razol's care. The pair subsequently rejoin the battle and later gather around their exhausted captain.

When Scheherazade appears on the battlefield and decides to confront the Black Djinn, Yaqut and the other members of the corps remain with her rather than withdrawing.

Razol is Yaqut's most frequently shown companion. They repeatedly fight and observe events together during the Magnostadt campaign.

Muu Alexius is Yaqut's captain. Yaqut follows him into battle and is comfortable enough around him to make lighthearted comments when Lo'lo sends him flying.

Scheherazade is Reim's Magi and the figure behind the King Vessels commanding the Fanalis Corps. Yaqut bows to her when she appears personally at Magnostadt and remains to fight beside her.

Myron Alexius and Lo'lo are fellow members of the Fanalis Corps and Yaqut's comrades during the Magnostadt campaign.

Morgiana shares Yaqut's Fanalis heritage and later encounters the Reim Fanalis Corps.