I'm DMing Wrath of the Righteous and we're about to start the Part 4 of the first book, in which Radiance will reveal itself to the paladin as being a legendary weapon.
The books says : "In addition, Radiance is a legendary item (Pathfinder RPG Mythic A dventures 169) that bonds with a mythic paladin as soon as it is wielded in combat-in this adventure, Radiance bonds if a paladin uses it in the final encounter against Vorlesh's babaus. The weapon has two daily uses of legendary power that recharge each day, but does not currently possess any legendary attributes, for it has yet to be wielded by a mythic paladin. As Radiance has its own ability to grow in power, it cannot be given the upgradable legendary item ability."
I looked rapidly at the others books and saw the evolution of the sword, being fully upgraded in a Holy Avenger in book 4.
But I wasn't able to track anything about its legendary powers. How does it supposed to work ? It is the same as if a mythic character would have taken the legendary item ability ? If so, why mentionning Radiance has two legendary Power use per day if it follows the normal rules for Legendary Items ?