Clearing up some lore misconceptions

[MercuryD]

Yshtola sees her sacrifice in Azys Lla and says:
EN: This aether... It was a crystal of light! She too was one of Hydaelyn's chosen!
JP: 彼女もまた、間違いなく、ハイデリンに導かれた光の戦士だったのね // So she too was undoubtedly a warrior of light guided be Her

(It's early so my translation isn't the best but it works)

[Zero-ELEC]

A fun read, real good document.

(It's early so my translation isn't the best but it works)

Yeah, it's established that all who received Her blessing and prove themselves find a crystal of light and are one of Hydaelyn's chosen, called Warriors of Light in the past.

The Warrior of Light is interesting in that they... receive multiple crystals of light? Which they needed to reignite to receive Her blessing again after their confrontation with Midgarsormr. That always struck me as odd, personally, and not really explained properly.