Complete summary (with spoilers)
On homeworld, the rebellion, led by Prince Argon and Slug, control the body banks, Karza’s power symbol. In his spacecraft, the fearsome Baron watches the scene behind the eyes of his prisoners, commander Rann and Marionette.
When he lands, bringing with him the two micronauts, he is defied by Prince Argon. This one, transformed by Karza in a centaurus form and wearing the holy armor of Dallan Rann engage the fight with all his rage against Karza. the battle is harsh between the prince genetically crafted to his horse Oberon and the Baron transformed too into his centaurus aspect. Protected by their strong armors, they shoot each other powerful blasts but the Baron is far more powerful than the prince of Homeworld and quickly, Argon lay down in the arms of Slug.
But, his recklessness didn’t be useful. During the fight, the Shadow priests, so-called faithful of Karza but, in fact, servant of the Enigma force, have deliver Arcturus Rann from the power-shackles of Karza and, more important, have awaken his memory. At this moment, The priests take away their robe and show their true form, the form of a Time Traveler and merge with Arcturus Rann, revealing the power he has gained in his 1000 years trip, the power of the Enigma force.
Karza’s dog soldiers, rebels, Marionette, Slug and Argon could only be the spectators of the fight between the two mighty enemies. Karza had already fight Ray Coffin transformed into Captain universe by a portion of the Enigma force but Commander is far more. He represents all the good things that Karza has trying to destroy during his reign: hope, love, nobility, comradeship. Even the might of Karza couldn’t win against that. The blasts of Karza don’t succeed to shatter the Arcturus’s force field. The commander use his power to force Karza to re-transform himself into his human form and increase his power as Karza’s power wanes. The win seem belong to the Enigma Force champion.
But the Baron refuses to lose so easily. He has succeeded to move the fight near the great pitt, a huge device witch permit Karza to drain power in the center of the homeworld planet, feeding not only the body banks but also himself. In a desperate action, he try to use all the power of the pitt and provoking a mind-shock capable of destroying homeworld, him and perhaps even Arcturus Rann. In a noising and luminous explosion of energy, Karza try to bind his power with the pitt. But another force strikes him in the pitt, leaving only his armor, empty, nearby the pitt, symbol of his reign. The tyrant was dead.
At this moment, the acroyear fleet arrives in the sky of Homeworld. In a few moment, the dog soldiers, demoralized by the death of their commander, are in a full rout. Acroyear, Cilicia, Microtron and Biotron can join their comrades. The time traveler, his mission achieved, quits Arcturus's body. The micronauts are reunited. The peace is back in the Microverse.