What always stood out to me when reading about the Children of the Light, were two major factors:


1 - The Aridhol Parallel:

One is how their organisation started out as a dedicated group of preachers who used words to bring Friends of the Dark back to the Light. The used peaceful methods to fight evil to the best of their abilities.
Slowly it deteriorated from people who fought only in self-defence to a misguided rigid millitairy organisation that executes innocent civillions in their Holy Quest against Darkfriends.

To me, it reeks like what happened to Aridhol, only this time it's not a city, but an organisation. Aridhol destroyed itself because they became creations equivalent of what they fought.
The Children have destroyed all they stood for, when instead of trying to convert Friends of the Dark relatively peacefully (using words where they could, and swords where they had to) they now choose to hunt, torture an even kill those they feel could be Friends of the Dark.
They've almost become that wich they once tried to convert.
They're sliding into Shadow with how they try to enforce their version of Truth.
And when you become like your enemy, you loose from him.

That brings me to my second major factor:


2 - The Light's equivalent of the Myrddraal:

Allow me some poetic leeway to call the Myrddraal "The Children of the Shadow". Truth be told, I don't think I really need a lot of leeway, but that might take too much explaining right now.

Still, if you just compare very visible chrarcteristics of the Children of the Light and compare them to the visible characteristics of Myrddraal, it's fairly easy to spot some similarities. It's these similarities and how they've deteriorated as an organisation that I view the Children of the Light as the human equivalent of the Shadowmen.

- Compare the spotless white cloak every Child wears to the jet-black cloak of the Fade. The trademark of the Children is scorned and they are ridiculed and named "Whitecloaks" behind their backs.

- Militairy-wise, the Children are a Heavy Cavalry army. It's true that we don't always see Myrddraal on horse, but in a full-scale war, we do usually see them on horseback. Makes sense. How else to keep up with their foot-soldiers; Trollocs who run nearly as fast as a horse.
I think it fits the picture. A black-cloaked rider in black plate always wielding a sword versus the white-cloaked armored always sword wielding man.

- The Hand of the Light (Questioners) versus The Hand of the Dark (again; a Myrddraal). Not only do the names match nicely, but also the role of the Questioners and one of the roles the Myrddraal have match; they're torturers.

As for their role in the Last Battle. My guess is the Questioners as a group will find a slow and painful death somehow. They have slid way too far into Shadow and will find a fate they deserve.

I'm hoping Galad will re-invent the Children as they were once meant when Lothair Mantelar started them. Preachers of the Light who will pick up the sword when they have to. I think Galad will lead a well organized Legion of Children of the Light and I hope they will square off in battle versus a huge group of Myrddraal (several thousand) all linked together -literary- fighting as one.
Both Children of the light and Children of the Shadow fight as "Legion". One group by choice and free will and the other will be totally controlled by Shai'tan or the Nae'Blis.

The prophecised "many will become one" doesn't just count for the Dragon in this case, but also for Myrddraal (where the word for one is the same as for thousands), for "His name is Legion, for they are many".
(if you don't know what I'm talking about, look up info about the demon Legion)

So..there you have it,
Cheers,
Mik