The legendary trait is a very rare trait that anyone can obtain upon character creation, once the eye of cthulhu is killed if the player has the trait the player will gain a buff called ???. After obtaining Legendary Super Saiyan the buff name changes to Legendary.
The passive effect of the legendary trait is x2 maximum ki, also granting access to Legendary Super Saiyan and Legendary Super Saiyan 2, which restricts Super Saiyan 2 and Super Saiyan 3.