The Spirit Bomb is an energy attack, exclusive to Goku only, that uses the power of planets, and lifeforms around him. He gathers in energy, causing the bomb to grow bigger in size. The Spirit Bomb is a bomb of PURE energy that evil cannot destroy. Goku has used this in many different periods. But the most well known is when he uses it to destroy the evil Kid Buu in the Majin Buu saga.