Mirai Trunks
Arriving unexpectedly from the future, Trunks immediately and without difficulty eliminates the greatest threat Earth has known: Frieza and King Cold. He is able to go Super Saiyan at will. And he knows things no one could know... like the exact time and place Goku will arrive back on Earth after his great battle against Frieza on Planet Namek.
Who could this mysterious stranger be? Trunks reveals the mystery in confidence to Goku. Trunks is from the future... a horrible future where evil Androids rule the Earth. This son of Vegeta and Bulma has come back in time to give Goku the antidote for a virus that will attack Goku's heart. He does this so Goku will live and help fight against the Androids. It is Earth's best hope.
But something has altered Earth's timeline. The Androids which appear are not the same as those of Trunks' time. They are more powerful. Trunks, too, enters the Hyperbolic Time Chamber to train in an attempt to become even more powerful than a Super Saiyan.
"Spending an entire year in the Hyperbolic Time Chamber was the most difficult task I've ever had to face. The gravity was so intense I could hardly walk. The air so thick I could hardly breathe. And the temperature fluctuated wildly-- sometimes freezing cold and others raging hot. Every day presented its own hardship-- a new obstacle to be met and overcome." But the time was well spent. Unknown to his father, Trunks' true power surpasses even that of Super Saiyan Vegeta.