Dragon Ball Z, Vol. 25

Sci-Fi martial arts action!
After years of training and adventure, Goku has become Earth's ultimate warrior. And his son, Gohan, shows even greater promise. But the stakes are increasing as even deadlier enemies threaten the planet. DRAGON BALL Z is the ultimate science fiction-martial arts manga.
Shorn of his last vestiges of goodness, the djinn Boo is now pure, undiluted evil! With a single wave of his hand he kills six billion people, leaving only the heroes in Kami-sama's sky palace alive...but for how long? Inside the palace, Goten and Trunks merge into Gotenks, the only being in the world who might match Boo in raw power. But luckily there's more than one world. On a faraway planet, Gohan and Goku are preparing for their turn to fight...to save the devastated earth before the planet itself is blown away!