A Fierce Fight! Double Mazingers

'''A Fierce Fight! Double Mazingers' (激闘! ダブルマジンガー Gekitō! Daburu Majingā) is the first episode of the Mazinkaiser'' OVA series. This episode was first aired in Japan on September 25, 2001.

Plot
Baron Ashura attacks Japan with an army of Mechanical Beasts with Mazinger Z and its allies standing in the way. However, Mazinger is overpowered and Koji Kabuto is flung to parts unknown. Dr. Hell quickly modified Mazinger Z into Ashura Mazinger which leads another attack on the Photon Power Laboratory. The damaged Great Mazinger's tries to defend the Lab but is pushed back and Tetsuya is about to be killed. Suddenly a large robot appears effortlessly defeating the Mechanical Beasts and Ashura Mazinger, and later attacks Great and the Lab!

Synopsis
Baron Ashura leads an army of Mechanical Beasts to attack Tokyo. Mazinger Z appears and defeats some of the Mechanical Beasts with help from Great Mazinger. Aphrodite A and Boss Borot also help in the fight but Koji tells them to back off believing the Mazingers can handle the Mechanical Beasts. But reinforcements come in and the robots are forced to retreat or suffer more damage. Koji however, refuses to retreat and as the Mazinger takes more damage the Hover Pilder ejects from Z sending him into the distance.

Baron Ashura brings the Mazinger to Dr. Hell who, in spite of being displeased with losing more Mechanical Beasts. takes delight in having captured Mazinger Z. Meanwhile Sayaka and Shiro go out to find Koji with Boss tailing. They see more Mechanical Beasts approach the Photon Lab and head back. The barrier is put up to protect the lab but later Baron Ashura pilots a modified Mazinger Z now called Ashura Mazinger. Tetsuya Tsurugi tries to fight Ashura Mazinger in the still damaged Great Mazinger but is pushed back.

Before Ashura could kill him and destroy the Great a giant robot appears effortlessly defeating the Mechanical Beasts and Ashura Mazinger. But as Baron Ashura retreats, the robot attacks Great and later the lab.