So what are legendary skills? A dev blog attempts to sort it out for those interested: “Legendary powers are more powerful and more exciting versions of the abilities you are already familiar with. To put it simply, legendary powers makes your favorite abilities even better! Whether it’s adding new effects, new mechanics, or simply powering up an ability to a whole new level, the legendary version of a power amplifies your power!”
The team provided several examples of these souped-up powers, including the Warrior’s Legendary Wavelength, the Cleric’s Legendary Explosive Rage, or the Mage’s ability to summon a second elemental to help with the fight.
Source: RIFT