How many Warrior of Light exist in story?

[Belhi]

The Player is the official 'Warrior of Light'. To be fair that is a label given by the public so really the fact only the Player is recognised as the Warrior of Light is because no one else has been yet. There can be more than one Warrior of Light at a time.

Storywise, the Player seems to be specifically Hydaelyn's chosen champion. Both Midgardsormr and the Ascians seem to suggest as much. She has many agents but the Player is a special case and Hydaelyn invested a lot of energy to protecting the Player while they grew in strength.

[Eloah]

I do not believe possessing the Echo makes one a Warrior of Light, because it seems to be an unspoken thing that the Warrior of Light's Adventuring allies also possess the Echo and thus are immune to tempering.
The primary qualifier to be a Warrior of Light is possessing not just the Echo, but ALSO the Blessing of Light. The two appear to be two completely different powers, as when Midgardsormr took away the Blessing of Light in 2.55, the Echo was a power our characters still retained. If anything, to have the Blessing of Light would require one or more Crystals of Light as well. The only other person with the Echo who also had a Crystal of Light that we know of is Ysayle, but that wasn't any indication that she had the Blessing of Light.

GAH!!!! What I originally wrote got deleted, I hope this is similar to my original, T.T

You are misinterpreting the context with the meaning. Similar to what Moose said, the phrase Warrior of Light has different connotations based on who and when you ask. In the present time the current usage is because the people are referencing the "Warriors" of Carteneau, whom they can only remember with a flash "of Light". But anyone with the Echo is one of Hydaelyn's Warriors of Light, they are just not referred to as such since that phase means something different to them. This is confirmed canonically by the 4 individuals I mentioned, The Warriors of Darkness, Y'shtola, and Matoya. But as I mentioned before not everyone with the echo will rise to prominence like the 4 we know of, some might not even know what it is as it manifest differently in each individual. But as someone mentioned in a later post, we do seem to be Hydaelyn's "pet project". Basically its like this, if you have someone doing something for you and they are doing a good job, you're gonna make sure they have the resources and tools to continue doing that job. Basically we are helping Hydaelyn, so she is helping us help her i.e. she gave us the blessing of light.

The Player is the official 'Warrior of Light'. To be fair that is a label given by the public so really the fact only the Player is recognized as the Warrior of Light is because no one else has been yet. There can be more than one Warrior of Light at a time. Storywise, the Player seems to be specifically Hydaelyn's chosen champion. Both Midgardsormr and the Ascians seem to suggest as much. She has many agents but the Player is a special case and Hydaelyn invested a lot of energy to protecting the Player while they grew in strength.

I'd say that's about right

[RokkuEkkusu]

I believe that in the ARR intro cutscene where the character meets Hydaelyn, Hydaelyn calls that person one of the "chosen many".

I am not sure if that implies that there can be more than one Warrior of Light. However, since the companions that fight alongside the character don't fall under primal influence and tempering, Hydaelyn might have a point.

[MiniPrinny]

-snip-

This. When you get your first crystal (water), you get to commune with Hydaelyn again, and in that cutscene there are hundreds, if not thousands of Warriors of Light. Every streak of light you see around Hydaelyn in that moment is a Warrior of Light.

What makes the PC different in the MSQ is that they are a Warrior of Light who has accomplished much more than defeating a weak ascian, they have bested trial and primal, one after another. They have overcome cataclysmic enemies.

The Warrior of Light that the MSQ follows is sort of the Elidibus of Hydaelyn's chosen many, the strongest and wisest. But they can't do everything, that's where the others come in, the lesser Warriors of Light do stuff that the PC can't, like take out ascians as needed or protect the people where the politicians fail.

Edit: I should note that me calling the numerous chosen lesser Warriors of Light is conjecture based on the events of 3.4. We saw that just a sole crystal of light was enough to overcome incredible odds and become god-like in power. So if we were to assume that everyone we saw at that moment were those with the Echo who had manifested a crystal of light. Then we as the Warrior of Light are likely far from alone, there just aren't many, if any, who have manifested all six crystals.

[Belhi]

This. When you get your first crystal (water), you get to commune with Hydaelyn again, and in that cutscene there are hundreds, if not thousands of Warriors of Light. Every streak of light you see around Hydaelyn in that moment is a Warrior of Light.

What makes the PC different in the MSQ is that they are a Warrior of Light who has accomplished much more than defeating a weak ascian, they have bested trial and primal, one after another. They have overcome cataclysmic enemies.

The Warrior of Light that the MSQ follows is sort of the Elidibus of Hydaelyn's chosen many, the strongest and wisest. But they can't do everything, that's where the others come in, the lesser Warriors of Light do stuff that the PC can't, like take out ascians as needed or protect the people where the politicians fail.

Edit: I should note that me calling the numerous chosen lesser Warriors of Light is conjecture based on the events of 3.4. We saw that just a sole crystal of light was enough to overcome incredible odds and become god-like in power. So if we were to assume that everyone we saw at that moment were those with the Echo who had manifested a crystal of light. Then we as the Warrior of Light are likely far from alone, there just aren't many, if any, who have manifested all six crystals.

Koji has said that Hydaelyn has many agents across the world but only one champion, one Warrior of Light. In truth its a title given by the people so there is as many Wariors of Light as the people say there are. For now the Player character is the only one who has been given the title by the general populous.

[Alleo]

This. When you get your first crystal (water), you get to commune with Hydaelyn again, and in that cutscene there are hundreds, if not thousands of Warriors of Light. Every streak of light you see around Hydaelyn in that moment is a Warrior of Light.

It is already confirmed that those people in that scene are not WoLs but just other people that she communicates with. At least right know we are her only one. (One could even say that we also werent the WoL at the beginning. We only got the title because we managed to collect the crystals, we did not start with one) Otherwise why should we defeat all those evils alone? Why are the ascians only worried about us? It seems that at least in the past we had more than one WoL, but Hydaelyn is losing this war so maybe she would not even have the power to protect more than WoL. I mean the WoDs came from a world with too much light, so maybe that is the reason they were more than one.