Dragon Ball Z Gaiden: Saiya-jin Zetsumetsu Keikaku

A mad scientist named Dr. Raichi arrives at Earth with the Dark Planet in tow, unleashing poisonous gas machines across the globe that threaten all life on the planet. Goku, Gohan, and Piccolo split up to locate and destroy these machines while contending with mysterious guardians, eventually reuniting to discover that four resurrected villains—Frieza, Cooler, Slug, and Turles—have been orchestrating the assault from Earth's television station. After a devastating attack forces the heroes to resurrect an island and gather supplies, they pursue Raichi into space, navigating alien worlds and overcoming environmental obstacles to breach the Dark Planet's defenses. There they confront not only Raichi himself but also his ultimate creation, a supercomputer named Hatchiyack that serves as the final embodiment of the Tuffle threat they must overcome to save Earth.