It would probably sound silly if I just said it no build-up, so apologies in advance for the rambling.

Hydaelyn's gift has different levels. It's possible to be granted the Echo and have nothing come of it; you wander around lost and confused and never know of your connection to Her. Some who heed Her call are gifted with slivers of Her power to carry out their tasks: a Crystal of Light. In times of unprecedented need, the blessing of Light might manifest through the crystal's power and protect Her chosen, as well.

But the Warrior of Light is a tier above all of these; this is Her champion.

Crystals of Light are drawn to the champion; it's possible for them to interfere with the aetherial realm itself to manifest them. This is why you only received one from Hydaelyn, and why the rest just appeared. (Fire from Ifrit, Wind from Garuda, Earth from Titan, Lightning as a gift from the Sylphs, Ice from Isgebind). It's a positive feedback loop; strength leads to being chosen, the Crystal leads to more strength, that strength in turn draws the Light.

In Toto-Rak, depending on your client language, Lahabrea's words are varying degrees of cryptic. In some languages, he goes full on Bond Villain and explains that you are a threat to him and why, lol.

Quote Originally Posted by Lahabrea
Je dois dire que ton cas me fascine. Je suis particulièrement intrigué par l'être qui t'habite...
I must say that your case fascinates me. I am particularly intrigued by the existence which inhabits you...

Il y avait bien longtemps que je n'avais pas vu un “Guerrier de la Lumière”, ce mal insidieux qui ronge la planète.
It has been a long time since I last saw a "Warrior of Light", that insidious evil which gnaws at this planet.

En plus de l'Écho, tu as le pouvoir d'interférer dans le monde de l'éther et de matérialiser des cristaux de lumière.
In addition to the Echo, you have the power to interfere with the aetherial world and materialize the Crystals of Light.
That flash when you strike Garuda is literally shearing the aether from her and forging a Crystal of Light with it, though you don't seem to be doing so consciously. Of course, it might be Hydaelyn Herself doing it, though the interaction between us and the crystals seemed to manifest even when Midgardsormr severed our connection to Her.