Dragonball: Dark light does not take place in the same universe as the original series. There are some constants, such as capsule technology, dragon balls, nameccians, sayians, etc. But no threat of Frieza, and the like.
In this world, nobody believed that dragon balls existed. As the people lived their lives, there was a force that moved under the radar. This force had a deep, dark agenda that hinged on exploiting an artifact that the people forgot. His (or should i say its?) first yet most difficult task had been realized. He had gained a power that many mortals could not handle nor comprehend. He had became an immortal. The next stages were simple. He had traveled by foot from land to land, challenging and destroying the populace and its people. He did not kill them for sport, but only killed those who stood in his way. The strongest of the world had failed to stop him.
It is now 500 years since then. The world is completely under his control. He rules the world from the lookout, and has scores of henchmen who have sworn fealty to him. His evil legions police the world while he rules from his ivory tower in the sky.