Berktes was a SuperHuman type Warrior Beast and the Monster of the Week on Ep.41 of the Great Mazinger Anime. It was mostly grey, with Green lines in the torso and forearms, it wore a a purple mask, a Yellow helmet, a red skirt with blue outlines, and the low legs were dark blue. His weapons were a Sword which he carried in the back, a Heat and Freeze rays in the palm of his hands, Missile launchers in the wings and two yellow Shurikens hanging on each side of his waist. It was capable of flight thanks to its red wings and a single large jet in the back. Berktes was one of the few Warrior Beasts to sport its human brain and true face in the head and was the first beast to be launched from Demonica when the Battleship was introduced.

A Robotic Fair is been assemble in foot of Mt. Fuji and this calls the attention of Mikene, as they learn that Science Fortress staff will be kept in charge of its security – viewing as an opportunity to attack, the Great Marshall of Hell brings forth the new Battleship Demonica and departs with the newest Beast to the Fuji area, digging its way from the sea. It emerges on the Fair Grounds while Boss Borot patrolling along with Bakarasu, destroying various Robots of the exhibit, and armed Mikenes Soldiers come out of the warship and take control of the area, surrounding Borot, who disguises itself as one of exhibits. Bakarasu flies to the Science Fortress and informs them of the situation and Borot's latest trouble. The Great Marshall contacts the Fortress, to boast, as well been aware of Borot (Borot winks to the camera). He then orders Explosive tanks to go after Borot, who takes action only to get its limbs blown off, and getting captured and sealed in a Balloon (No joking, they sealed them in a large Balloon attached to a rope).

By morning, and with options running out, Tetsuya and Jun go on their Mechas to fight them, as the enemy begins to launch missiles at them – Great Attacks Demonica, its attacks making no effect on the ship's hull, only to confront Berktes, while Venus A, trying to save Borot, get herself and Borot surrounded by more Explosive Tanks, which proceeds to fight them with her projectiles. Berktes incapacitates Great with its freeze ray, the Mecha crashes into the lake, which he proceeds to freeze over, Venus A runs towards Great to help out, but is defeated by the Berktes when is hit by its Shuriken and Heat Ray.

With the three Mechas out of commission, The Great Marshall demands Kabuto to surrender, to which he accepts, but tells his staff to contact Tetsuya and orders him to attack the Ships Command Center. Kenso then leaves to surrender himself. Shiro calls Tetsuya and warns him and Great Mazinger Breaks free with the Breast Burner, Berktes tries to keep him at bay with his rays at first, but Great rips a hole in the stomach with a Pressure Drill Punch and shuts it down with Thunder Break. Great then throws its Boomerang, ripping its forearms before it could use its rays. Berktes wounds Great with its Shurikens, but the Mecha kicks him and finishes the Beast off with the Great Burner.

As Kabuto arrives surrounded by Soldiers, Tetsuya puts Venus A on a safer place when it takes off to attack Demonica – he arrives, blast off some of the Mikenes Soldiers and rips through the command tower, wounding the Marshall. With their commanded wounded, Demonica retreats, much to the protests of the Great Marshall.