Super Saiyan (DBUS)

The ability to become a Super Saiyan was once considered to be nothing but a legend, because it had not been performed for over one-thousand years. Vegeta first stated that a Super Saiyan has achieved a level of power so overwhelming that it could only be maintained in a transformed state. However, when this legend was proven to be true when Goku accomplished the feat during his titanic battle against the evil tyrant Frieza, he maintained this state in his original form. Despite only being told through legend, Frieza, considered to be the strongest being of his time, became paranoid over the possibility of truth behind the legend of the Super Saiyan, as evidenced by the constantly growing power of the Saiyan race. Because of this fear, Frieza drew the conclusion to annihilate the Saiyan race by destroying Planet Vegeta (Note: Some Saiyans were on another planet so not all of the Saiyan race was killed), thus sparking the end of the Super Saiyan legend.

According to Goku, the Super Saiyan transformation comes in response to a need, not a desire. In all known cases, the form has been initially triggered by either desperation or indignation. Any other conditions are unknown, and motivation tends to differ; for example, Goku achieves the form out of anger over the murder of his best-friend, Krillin, and Vegeta achieves the form through sheer frustration at his original inability to achieve it, especially over Goku. While training in the Hyperbolic Time Chamber, Goku tells Gohan that becoming a Super Saiyan is powered by rage and told him to imagine Cell, and then Frieza when Gohan said he had never seen Cell, killing all his friends to transform into a Super Sayian. Saiyan hybrids are naturally skilled at this, as they have the emotion of Humans (full blooded Saiyans tend to suppress their feelings) with the fighting potential of Saiyans. As the Saiyans train during Dragon Ball Z, Dragon Ball GT, Dragon Ball Ultimate Saiyans, they discover uncharted levels beyond the first Super Saiyan level. The appearance of a Super Saiyan is different in each form, more so in the fourth form.