Seven-Three's History
Background
Seven-Three was created on a planet with advanced science and technology along with other OG Soldiers, who all belonged to a man named Goichi, who desired to rule the universe. Somehow, Saganbo and his Galactic Bandit Brigade encountered Seven-Three and added him to their group. Seven-Three then rampaged throughout the universe with them until they were caught by the Galactic Patrol, Merus specifically, and imprisoned in the Galactic Prison.
Galactic Patrol Prisoner Saga
Alongside the other prisoners, Seven-Three is released by Moro's second wish, they then proceed to take over the facility and re-secure Saganbo's Spaceship - promptly using it to head to New Namek.
Seven-Three accompanies Moro and several other members of the Galactic Bandit Brigade to Zoon, where they attack the warriors guarding the royal treasure. After defeating them, one of the warriors makes a final attempt at killing Seven-Three, resulting in the artificial being wiping out all of the warriors with his eye lasers, much to the disdain of Saganbo, as they were supposed to keep as many alive as possible for Moro to take energy from.
After Moro and Saganbo receive a report of powerful life-forms on the planet Earth from the Macareni Gang, Seven-Three is deployed there alongside Shimorekka and Yunba to scout the place. On their way there Yunba begins to complain about wanting food, leading them to stop on a planet inhabited by hedgehog-like humanoid aliens, Seven-Three copies their powers and kills them while Shimorekka and Yunba eat their food. Seven-Three then notices one of them with a portal-creating ability escorting children to safety and promptly copies the ability, he then uses it to go to Earth alongside Shimorekka and Yunba, appearing on the Lookout.
As Piccolo stops Shimorekka from killing the Macareni Gang, Seven-Three quickly copies his powers. Seven-Three attacks with a Special Beam Cannon that Piccolo barely dodges, and knocks Jaco off the Lookout with his Demon Hand, he follows Piccolo when the Namekian leaps over the edge to save Jaco. Seven-Three and Piccolo then engage in combat, going blow for blow and using the same moves. Jaco reveals that Seven-Three has unlimited stamina, and so Piccolo is bound to lose unless he can hold off Seven-Three for half an hour, Seven-Three proceeds to overpower Piccolo in a Special Beam Cannon energy clash, however Gohan swoops in just in time to save his mentor.
Gohan lands a few hits on Seven-Three, but Seven-Three fires multiple Ki blasts around Gohan, using the Hellzone Grenade. It looks like Gohan is hit with every blast, but Jaco spots him standing behind Seven-Three. The android is flown across the fighting area, and Gohan reveals that he's used to fighting against Piccolo and knows how to counter his techniques. Seven-Three gets back up and uses Piccolo's Great Namekian transformation to turn himself into a giant. Gohan says he's used to this too and continues to gain the upper hand on Seven-Three. After Seven-Three is knocked down and getting back up, Shimorekka tells him to get his hands around Gohan's neck. Seven-Three agrees and stretches his arms out to get to Gohan. Gohan dodges them, building up a Kamehameha and running up Seven-Three's arm. Gohan then jumps in front of Seven-Three's face, but at that moment Seven-Three shrinks back to normal size. Jaco points out that Seven-Three's time with Piccolo's powers have expired, so Gohan points his Kamehameha down at Seven-Three and fires. However, one of the orbs on Seven-Three's head has a picture of Moro, sliding into the middle orb. Before Seven-Three is hit with the Kamehameha, it seemingly disappears, with Piccolo stating that he ate it.
It's then revealed that Seven-Three can copy up to three powers at once, and switch to different ones if necessary. Seven-Three begins to absorb energy, fending off anyone that tries to stop him. He continues to absorb energy, forming a large energy ball above himself while Shimorekka and Yunba fight the others. As the fight continues, Shimorekka gets a call from Moro, who tells them to come back to the main force. When Seven-Three hears this, he stops absorbing and disperses the energy ball. His power then switches back to the Zoon race as he creates a portal for himself, Shimorekka, and Yunba, and the three of them leave Earth.
Two months later, Seven-Three re-appears with Moro and the Galactic Bandit Brigade on Earth. At some point prior, Seven-Three used his copy ability to gain invisibility from a member of an invisible race and uses it to sneak behind Gohan and Piccolo and obtain their abilities. Seven-Three fires a Special Beam Cannon at the pair, but Gohan blocks it with a shield made of energy. From behind Gohan, Piccolo powers up and fires a Special Beam Cannon of his own that hits Seven-Three and destroys an upper portion of his body and left arm, though he regrows it thanks to Piccolo's Namekian Regeneration abilities.
Shimorekka tells Seven-Three to switch to Gohan's abilities, as he is the stronger of the two. As he does so, he fires a volley of energy blasts towards them. Gohan charges forward, using Piccolo's assisted energy blasts as footholds to close in quickly, and punches Seven-Three into the sea. As Gohan vows that they will never lose to a copycat, Seven-Three emerges from the water. Gohan and Piccolo unleash the Masenko Beam Cannon that once more severely damages Seven-Three, though it does not finish him off.
Shimorekka urgently tells Seven-Three to switch to Moro's abilities and he does, with the plan to drain their energy, but before he can he is suddenly kicked in the face by the arriving Android 17 and Android 18 with Piccolo pleased to see them as they do not have energy that can be absorbed. Android 17 proceeds to pummel Seven-Three and almost finishes him off but Moro intervenes which effectively puts the fight to an end. Moro tells him that he should not have used his abilities so casually and tosses the injured Seven-Three to Shimorekka, ordering him to help him recover as he begins to take him back to their ship.
Later, after being greatly weakened during his battle with Vegeta, Moro returns to the ship, where he kills Shimorekka without a moment's hesitation and proceeds to swallow Seven-Three alive and whole. This provides Moro with a substantial boost in power along with a new appearance that is one part Seven-Three. Moro explains to the Dragon Team that he didn't just have Seven-Three copy his magical abilities, but his combat abilities as well, creating a complete backup of himself that existed inside Seven-Three.
Granolah the Survivor Saga
Ultimately, Moro was defeated by Goku but Seven-Three survived albeit in a heavily damaged state. Upon letting out a faint distress signal, he was found by two of Goichi's henchmen and was returned to his original owner where he was placed in a rejuvenation chamber. Having been input with a lot of data during his time with the Galactic Bandit Brigade and having become much more powerful, Goichi ordered that the data from Seven-Three to be placed into all the other OG Soldiers. Granolah later boarded the ship where Seven-Three was located in search of him.
After being secured, Granolah takes Seven-Three to the Heeters. Elec reveals that he plans to use the intel stored within Seven-Three to locate Zuno.
