While Goku’s ability to go Super Saiyan is insanely powerful and has helped him win a number of high-stakes battles over the course of his Dragon Ball career, the transformation has one secret power that makes Goku even stronger–under the right circumstances, that is.
Goku first unlocked the power of Super Saiyan while battling Frieza on Planet Namek. After Frieza killed Krillin right in front of him, Goku channeled the blinding rage he felt at that moment into the energy he’d use to become a Super Saiyan. From that point on, Goku was able to utilize the transformation at will, and he used it in pretty much all of his subsequent fights–including one in particular where he discovered that the Super Saiyan form could give him yet another advantage in battle.
In Dragon Ball chapter 450 by Akira Toriyama, Goku, Gohan, Vegeta, and Supreme Kai have tracked Babidi, a villainous sorcerer, to his underground lair where he hoped to awaken the seemingly all-powerful Majin Buu. Before Babidi succeeded in his potentially world-ending mission, the Z-Fighters knew they had to stop him by any means necessary. So, they followed the sorcerer into his underground lair where there were increasingly powerful villains set up on each level, waiting for the Dragon Ball heroes to attack–and one of them was a giant green monster called Yakon.
Goku’s Super Saiyan Form Gave Him the Edge He Needed Over Yakon
One of Babidi’s more intimidating abilities is his power to transport people to different locations, even if those locations are across the cosmos. When Goku faced off against Yakon, Babidi transported everyone to Yakon’s home world, one devoid of light and engulfed in blinding darkness. Goku couldn’t see a thing whereas Yakon was used to operating in the pitch black landscape and thrived on this battlefield. However, just as Yakon thought he would be victorious, Goku powered up to Super Saiyan and the light he emitted from his very body was enough to not only allow him to see Yakon, but also momentarily blind the creature–giving Goku a much-needed edge where he otherwise was at a massive disadvantage.
While it was revealed immediately after this exhibition of an unexpected yet totally obvious power attributed to the Super Saiyan transformation that Yakon could actually absorb light energy, that doesn’t negate the fact that powering up to Super Saiyan allowed Goku to see in a place where there was no light. Being a Super Saiyan allows someone to become their own source of light, just from the energy within themselves. For a fighter like Goku who oftentimes finds himself in the far reaches of the Dragon Ball universe, this is a pretty handy ability to have–proving that Goku’s secret Super Saiyan power makes him even stronger.