The easiest way to think about it is that while Hydaelyn has gifted the Echo and Crystals of Light to many, the PC is the one, true Warrior of Light.

Various bits and pieces in-game suggest this; Unukalhai's journal entry for Zurvan mentions you gathering a group of "echo-blessed champions" to take on the Demon, but in terms of story you are the one and only Warrior of Light.