Why Goku’s victories usually stop short of a kill
Dragon Ball Z gives Goku a remarkable amount of power, but power is not the same as a willingness to finish every fight lethally. Many of his major opponents survive because he chooses to spare them, or because another character delivers the decisive blow. That pattern makes the two deaths attributed to him stand out—and they happen in very different ways.
Yakon is overwhelmed by the power he tries to consume
During the battle aboard Babidi’s spaceship, the monster Yakon can absorb energy and uses that ability to feed on Goku’s power. Goku responds by increasing his output so dramatically that Yakon takes in more energy than he can handle and bursts apart. It is a kill caused directly by Goku’s attack, though not a conventional finishing move: Yakon’s own hunger for energy turns against him.
Kid Buu requires a different kind of finish
The final battle is more deliberate. Kid Buu is an exceptionally dangerous enemy who keeps recovering from damage, so simply overpowering him with ordinary attacks is not enough. Goku gathers energy for a Spirit Bomb—a sphere of borrowed energy—and hurls it at Buu. With help that restores Goku’s strength at the crucial moment, he pushes the attack through and destroys Buu.
The contrast is the memorable part: Yakon dies because Goku exploits an opponent’s ability, while Kid Buu is eliminated only after a prolonged effort to end a threat that will not stay down. Most of Goku’s other landmark victories leave the killing to someone else—or leave the defeated enemy alive.
