Metal Series

Six premium robots make up this squad, each carrying its own distinct design. Metal Pawn, Metal Rook, Metal King, and the Metal Knight unit are built along humanoid lines, while Metal Queen and Metal Bishop break from that mold with unusual, non-humanoid frames. Although a remote operator can pilot them, every member is also capable of fighting on its own.

Coordination is the squad's defining trait, and its members chain their attacks together to fight as a single unit. Dr. Bofoi holds the group in high regard, treating it as a trump card powerful enough to brush aside any threat that comes his way.

The Metal Series functions as Bofoi's decisive strike team, held in reserve until an enemy needs to be crushed quickly. Their coordinated combat style lets them overwhelm foes that would be difficult for any single robot to handle alone, and Bofoi keeps them close as his answer to serious danger.

The squad sees action during the Robot Invasion Arc. When Isamu confronts Bofoi at his base over suspicions that Bofoi is behind the robot invaders, the standoff turns violent and Child Emperor calls in his trump card, the Super Brave Giant. Bofoi answers by throwing the entire Metal Series into the fight.

The squad tears into the Super Brave Giant with synchronized assaults, chipping it apart piece by piece and reducing Child Emperor to tears as his giant is dismantled. The rout is cut short when Genos, racing toward Bofoi's base, barrels through and punches clean through the failing machine, finishing its destruction.

The roster is all robots and all listed as active: the Metal Knight unit, Metal Rook, Metal Pawn, Metal Queen, Metal King, and Metal Bishop, every one of them serving as a squad member under Bofoi's command.