The Super Saiyan concept was first introduced as a legend in Akira Toriyama's Dragonball manga. The legend states that once every 1,000 years, a Super Saiyan with unlimited powers will appear. The first character to actually realize the transformation, was the series' protagonist, Son Kakarot, during his fight with the galactic overlord Frieza. Later throughout the series, several more Saiyans achieved this level of power, dismissing its status as "legendary". Furthermore, several ascended levels of the transformation were obtained by various Saiyans.
When Kakarot made his first transformation, it happened out of sheer rage and hatred towards Frieza, who had just killed his best friend, Kururin. Later, as the Saiyan grows more familiar with the transformation, it can simply be realized by increasing a certain type of energy within the body, called ki. When transformed, a Saiyan has access to whole new levels of strength, speed, and much better reflexes. Goku for example, increased his power fifty fold when he first transformed. It is unknown if this increase also applies to other Super Saiyans and as the series progress.
Super Saiyans are very easily recognized. The hair becomes blonde and stands very upright (Exception is made for Super Saiyan 3). The eye color of the Saiyan changes from their natural, to turquoise. Furthermore, a golden aura will appear around the Saiyan. This aura can be switched on or off at will.
 Gender Controversy
When Toriyama created the character Pan, daughter of Son Gohan, and thus grand daughter of Kakarot, he received many questions by fans, wondering if Pan was also able to achieve the Super Saiyan transformation. In the 7th Daizenshuu, Toriyama wrote that this was impossible due to Pan's Saiyan nature having become diluted. A Saiyan can only achieve Super Saiyan if his blood is at least 50% Saiyan. Pan was only 25%, rendering her incapable of transforming. Later however, Toriyama revealed that he couldn't come up with a female Super Saiyan design. As such, the diluted blood theory can be considered a cover-up.
To add further controversy and confusions, Toei Animation later made Kakarot Jr, and Vegeta Jr, descendants of Kakarot and Vegeta, Super Saiyans as well. With Pan being quarter Saiyan only, their transformation is logically not possible due to their Saiyan blood being even more diluted than Pan's.
 Characters that used this transformation
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