Shenron first taught Goku this technique during their training prior to Dragonball SV, but much to Shenron's suprise Goku had actually used it before, but had not recognised its true power. It has the power to multiply the power of a super saiyan to ridicoulous heights, even Goku using it once to gain 1 million times the power of a super saiyan 5 for a few minutes to be able to defeat the Dark Namek Zaecor I.