"Returned to the living world, Goku cannot control his power. Super Saiyan 5 makes him go evil and transform into an evil being. Now Vegeta has to become the star. Vegeta will unlock a new form (SSJ5? I'm.. not sure) and he beats Goku, becoming the strongest actually! And the hero! But of course, Goku is 'returned to his senses', or it's revealed that an evil demon was in his soul controling him (depending on which site)."