Giga tested the Deathballs, by hitting one off a makeshift tee stand on their deserted island. It destroyed an observation plane sent to investigate their recently surfaced real estate. Giga appeared grim and expressionless, which probably means he was jumping up and down and doing happy somersaults inside.
Pleased with the Deathballs' performance, Mega gave them to Hydra and Buster. They equipped their planes to either fire Deathballs at high speed, or scatter them in a barrage, and used them in their plan to flush out the recently-awakened Autobot Godmaster Ginrai.