shonenhikada wrote:In the Freeza saga we saw that Goku, when he fought with Freeza, was using the kai-o-ken x10 and there was no noticeable change in his appearance from the reader's point of view.
Well, there sort of is. He does this right before Kaio mentions him using Kaioken x10:
It's only the anime that adds in the stuff about him using Kaioken too quickly to be seen.
He then used the kai-o-ken x20 to combat Freeza when he was 50% his maximum. Now here comes my theory: after using kai-o-ken x20, Goku's ki was said to have shrunk, he then began taking a beating from Freeza which would have lowered his PL even more. But the fact that he survived all this without dying indicates he was still using the kai-o-ken. Now Freeza gets hit by the spirit bomb, pops back out, kills Krillin, and Goku becomes a SSJ. The thing is, Goku could have still been using kai-o-ken x10 with the transformation, which would indicate the SSJ form only increases 5x that of base, which seems to hold true in the later arcs of the series. Also I don't believe Goku was at 150 million when fighting Freeza, because Piccolo commented that Goku's ki got smaller, and he also took that beating which would have reduced his base to below the 3 million mark. Which is why the fight with Freeza dragged on so long despite Freeza being at 120 million.
Some other people have put forward this idea as well. It's possible that Goku wasn't at his best, but on the other hand, his fatigue seems to go away the moment he becomes a Super Saiyan, as though he's tapped into a new well of power that he didn't know about. Some people liken it to an adrenaline boost.