Ruben Chagar

Ruben is loyal, disciplined, and serious about the Crimson Lions' reputation. His devotion to Fuegoleon remains strong even when Mereoleona temporarily assumes command.

He is also practical enough to follow stronger tactical leadership. During the Royal Knights Selection Exam, he quickly accepts that his team's best strategy is to support Rill rather than compete with the captain for control of the battle.

Ruben can become exasperated by Rill's tendency to lose himself in artistic inspiration, but he continues compensating for the captain's distractions rather than abandoning the plan.

Ruben uses Sandstone Magic, generating and manipulating sandstone.

Variable Hardness Prison allows him to create sandstone restraints with adjustable durability, giving him a useful method of immobilizing opponents.

He can also use Reinforcement Magic and Mana Skin, reflecting the training he receives with the Crimson Lions.

After being freed from elf possession, Ruben retains some of the additional magical power associated with his elven host.

Ruben first becomes prominent when Mereoleona berates the Crimson Lions for falling in the squad rankings and forces them to train at Ultime-Volcano Mountain Trail.

He later enters the Royal Knights Selection Exam on Team I alongside Nils Ragus and a mysterious participant who reveals himself as Rill Boismortier.

Ruben and Nils largely support Rill during the tournament, destroying opposing crystals while the captain occupies stronger enemies. Their team reaches the final round before Rill accidentally destroys his own crystal while battling Yuno.

Ruben nevertheless performs well enough to be chosen for the Royal Knights. He enters the Eye of the Midnight Sun's base alongside Rill, Fragil Tormenta, and Puli Angel.

When the elf reincarnation begins, Ruben becomes the vessel of the elf Rossa and temporarily turns against the Clover Kingdom. He later returns to himself when the reincarnated souls are released.

Fuegoleon Vermillion is the captain Ruben respects deeply and remains loyal to throughout his service.

Mereoleona Vermillion temporarily commands Ruben's squad and subjects him to extreme Mana Skin training.

Rill Boismortier leads Ruben's team during the Royal Knights Selection Exam and later commands his group during the assault on the Eye of the Midnight Sun.

Nils Ragus is Ruben's closest tournament teammate, frequently working beside him to support Rill.

Rossa is the elf who possesses Ruben during the reincarnation crisis.