The following story is how I would have made Dragonball Z I do not own Dragonball, Dragonball Z or any affiliated works The following work is free fan fiction. Not for sale.
Prologue: The lost history of the Saiyans
Twelve hundred years had passed since the saiyans had lost their home. A planet once lush and green, it had been withered and frozen by the dying of it's star. Rather than succumb to an icy death they took to the stars, and traveling from one solar system to the next they searched for a new home. For centuries they searched, a migrant fleet of decaying vessels. Some formed into smaller groups and sought to change their cursed luck, but none now know what became of them. Perhaps they too found a home, but it sadly likely that they did not.
On the quincentennial of their exodus, the saiyan fleet found what they sought. A living world with the resources to support them. A place where they could end their arduous journey, and none too soon. Their ships were nearly crippled, and they would not have made it to any other place. They knew in their hearts that fate itself had guided them there. Only one potential obstacle now lay before them. What would the planets current inhabitants think of all this?
The native race, the Toffles, were a diminutive species. Slight of build and physically weak, but gifted mentally. They had created a technologically advanced civilization for themselves, but had no definitive knowledge of life beyond their world. All that changed with the arrival of the saiyans. Though the saiyans themselves were diverse in size and intelligence, and had many gifted scientists, their technology was vastly inferior to that of the toffles.
The saiyan's ruling council met with the hierarchy of the toffles and after a many months of confusion and overcoming the rather sizable language barrier, the two parties reached an accord. The planet Yelden (as the toffles called it) was comprised of six continents. The toffles themselves lived primarily on two of these, located in the most temperate zones of the globe. To the saiyans they offered the smallest continent, which lay on the opposite hemisphere, harsher and more wild than the places where the toffles resided. To the saiyans, this was better than they had dared to dream.
Over the course of the following decades, the saiyans thrived. Rebuilding their civilization and multiplying rapidly in their prosperous new surroundings. The two races learned much from one another, though neither told the other all that they knew. The saiyans learned about incredible new technologies to assist in their lives, and the toffles learned about energy. Not the kind of energy you get from the sun, or from a machine, or even fire. This was living energy. The kind that could be harnessed from within oneself to take a being far beyond their physical limits.
Nearly two hundred years had passed with each species living in relative harmony with the other (though always at arms length), when a problem began to arise in the minds of many toffles. The saiyans were expanding too quickly.
It had not been so long ago that the saiyans had arrived on Yelden, and already they were seeking permission to settle another continent. The toffles too, had a growing population, and were seeking new places to settle. A conflict was bound to arise sooner or later. And while the toffles had the edge when it came to weapons of war, they were wary of the saiyans' ability to manipulate energy. Energy being, after all, an area that the toffles were not very adept at.
The peace held for another century when the flames of a brief, but bitter war, roared to life. Skyrocketing populations and dwindling resources led to the inevitable result of bloodshed. Though the saiyans wreaked havok with their abilities it was the toffle's technology that allowed them to come out on top, and the saiyans once again were nearly extinguished.
Those that survived were taken captive and put to work repairing the damage they had wrought. The saiyans feared that they would be murdered after their labor was done, but the toffles had found the saiyans physical attributes to be incredibly useful. So instead of death they were enslaved.
For more than three hundred years the saiyans were bound by their masters. Only the strongest were allowed to have offspring, and soon the great minds of the saiyan race were no more. All that remained were warriors. Forced into labor, or to fight one another to the death for the amusement of their keepers.
But this selective breeding of the saiyans had an unintended side effect. It forced a backward step in the saiyans' evolution. Making them inherently bloodthirsty, ruthless, and brutal. It also unleashed a power that the saiyans themselves had forgotten before they ever left their home world.
The night of the full moon was a celebration for the toffles. A sight they saw but once in a lifetime, for it occurred only once every hundred years. On that night, the toffles realized their doom. On that night, they reaped what they had sewn. And as the moon rose into the night sky, veiled by clouds, the people of Aldan waited in anticipation. When the clouds parted, however, they got something they did not expected. The saiyans stared up at the moon, and began to change.
Their breathing came in raspy heaves, their eyes changed from their typical coal-like dark color, to angry red. But what happened next, the toffles found truly terrifying. The saiyans underwent an excruciating transformation, growing, towering over buildings, taking the form of giants apes. And the pain of it drove them nearly mad with rage. Most forgot who they were, and knew only how to destroy. When they awoke the next morning, blood-soaked and naked, the toffles were gone, and all that lay about them was devastation.
Over the weeks and months that followed, the saiyans pieced together what had happened to them. In the ruins of what had once been the toffles' civilization, survivors were found. Only a few at first, but eventually many hundreds were assembled. Some called for enslaving them, others execution. But there was one saiyan, one of the few who had remembered in full what had happened on the night of the full moon, who was more cunning than all and stronger than most, who thought he had a better idea.
He used his power to gain dominion over his rivals, and become a great leader among the saiyans. It was he who sentenced the toffles to exile. To take to the stars and wander aimlessly in hopes of finding a better world. The other saiyans delighted over the thought of the toffles slowly suffering as their ancestors had, and to reward this man for his power and his cunning, the saiyans made him their king. They re-named this world which was now theirs in his honor. His name, was Vegeta.