The Legendary trait is a very rare trait, having a 5% chance of getting the trait upon character creation, or by using the Dragon Balls. 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 and saying "You are the saiyan from the legend" . The bar will be of a different color depending on the trait, in this case the Legendary Trait.
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 access to Super Saiyan 2 and Super Saiyan 3. Super Saiyan God also cannot be used on command while having the Legendary trait, though it can be used when you pick up a Godly Spirit until you run out of ki.