The Mysterious Fifth Man Dragon Ball: Doragon bôru : Season 1 Episode 74

Akkuman has a rough battle against Goku’s overwhelming power, and fires the Devil Might Beam. It’s a frightful attack that infinitely multiplies the tiny evil hidden without a person’s heart, causing them to explode! Goku is bathed in the Devil Might Beam, but for some reason it doesn’t work on him! It turns out that Goku somehow doesn’t possess an evil heart!! Goku finally blows Akkuman away! And then the fifth man finally appears, but for some reason Goku feels nostalgic.