"For a long time I thought Super Saiyan 4 was the summit of Saiyan strength. This form reveals a whole universe of strength waiting to be mastered..."
— Super Saiyan 5 Goku to Vegeta
GSuper Saiyan 5 is the successor of the Super Saiyan 4 form. Since the latter was described as the summit of Saiyan power, the incredible power of Super Saiyan 5 is often gawked at, and frequently overrated. This form has never been achieved by any saiyan before, making Goku the first one. In order to achieve the form, one must harbor enormous energy, full mastery over every Super Saiyan form, and must face an enemy so powerful, no means of the saiyan's power can beat the foe. They must peacefully exert all their power without blowing themselves up, indicating peace of mind. This reaction will cause the transformation of Super Saiyan 5.
The Super Saiyan 5 form is an extremely rare power up technique reserved to inconceivably powerful members of the Saiyan race (much like the Saiyans of the Z-Fighters). The form itself is extremely rare to get, therefore no Saiyans before have unlocked the secrets and powers of the SSJ 5. The form has some requirements beforehand the transformation. First, the Saiyan must have full-mastery of all previous Super Saiyan forms. That also means harboring enormous amount of energy, only through training. In the time before the transformation, the Saiyan has to be in SSJ 4 form. He/she must be facing an enemy that can't be defeated by any means. As a result, the Saiyan must resort to the self-destruction technique. But this time, the Saiyan has to be in peace of mind. He must have no worry over killing himself. Then he must unleash that power, thus transforming into SSJ 5.
"Wow, even I don't even reconize myself anymore..."
— Super Saiyan 5 Vegeta
The appearance of the SSJ 5 drastically changes from any other formal Super Saiyan forms. The red fur in a Saiyan's body is turned to any purplish-hue, along with the tail. The Saiyans adopt the same pants, just a little darker and more vibrant. The hair turns into the color of the Saiyan's fur and is as long as Super Saiyan 3's. Unlike, SSJ 3 though, the Saiyan retains his eyebrows. Muscle mass increases dramatically, making the Saiyan look muscular and sleek at the same time, similiar to the Saiyan's actual capabilities. Skin also turns a bit redder, due to increased blood flow.
The first Saiyan to unlock this form was undoubtedly our hero Goku. He unlocked this form against his the Saiyan Swordsman Hikaru. When Hikaru killed his friends and family (with the exception of Goku Jr., Vegeta Jr, Tora, and Vegeta), Goku involuntarily exploded in rage, releasing a self-destruction bomb. But at the last minute, he got a hold of himself and got himself together when he unleashed the attack, unexpectedly transforming into SSJ 5. The form is accessible anytime after being accessed the first, much like its former form. Vegeta transformed when he realized Goku has surpassed him once again, mimicking his rival's transformation, and transforming into one himself.