What is a Warrior of Light?

[Delily]

So as far as the primary story is concerned, there is only one champion-warrior of light, but there are at least a handful of others with lesser degrees of Hydaelyn's blessing?

A lot of people are confused by the difference between the Echo and the Blessing of Light. I believe most of the scions have the Echo. That grants a person resistance to the tempering effect of primals, the ability to understand multiple languages, and the power to see things from another person's perspective.

The Blessing of Light is a distinct power that has only been used, as far, as I can tell, once, and that was during the battle with the Ultima weapon. It some defense against Zodiark's power, but I don't think it's been formalized as to what the blessing is. It's tied to the crystals a person has; we have all 6, Ysayle had 1.

The Warrior Of Light is therefore an individual who has the Blessing of Light. I think the only other warrior was Ysayle.

Another concern has to do with each individual's strength. Ysayle was clearly very powerful, as summoning a primal into her body and controlling it is not an easy task. An issue that was hinted at in the end of HW and then revisited in 3.1 is how our character is not just powerful, but probably the single most powerful entity on Eorzea. We're not strong enough to take down the Empire singlehandedly, but we've (lorewise) fought alone against various primals. The scales are tipping in the favor Light, but it's not confirmed that's a good thing.