>Opal Ability:
One thing before actually going to discuss it, is that her ability is a wizard ability and should be held to a different standard than a SAC.
The same wizard and a SAC ability can have the same wording but wildly different effect due to simply SAC being able to scale it far beyond.

>reflect
The wording seems to be that the blind effect is a consequence of reflecting a bright light. Which would make sense as if you shine a flashlight into a mirror then the reflected light might blind you if it's directed on your eyes.

>I would suggest that it might reflect effects that are a pure consequence of the light, for instance light damage or inflicted blindness.
All the effects of spells are caused by magic and not a pure consequence of the light. This is magical light and is why you can't penetrate an Antimagic field with it. And this isn't a magical reflector, but a light reflector
Things that are a consequence of magic generally aren't affected by Antimagic and similar. If you cast [Fly], pick a rock and drop above an Antimagic field then that field won't do anything to the rock, but if you use a spell that creates and throw the rock at it, it won't work at all. The same is true here in what is a consequence vs what isn't a consequence.

>Helel Ability
It should be toggeable like Ainz abilities.

>Suitably adjusted
That is actually what Zuranon said. I made this ability while discussing it with him.
But as I said on the thread, one of the ways to think of it is as Snowcasting:
https://dndtools.net/feats/frostburn--68/snowcasting--2670/
That is the adjustment.

Though Zuranon was thinking like the spells would gain extra effects or have their effects changed a bit. However this is basically impossible for we to guess what would happen exactly to the spells.

>This probably means no darkness effects
The [Light] is added on it, it do not replace the  [Dark] that is in it.

>The Light Subschool
Let me explain it. The [Light] subschool was conceptualized as the [Shadow] subschool but with the element switched to [Light], this was done in order to suit the changing Helel fluff.
Originally Helel was a Conjuration/Evocation specialist, but as time went, things changed and her background got more detailed(she didn't have a name for 10 versions or so), and it went to a background of an Atheist Angel who dedicates herself to light but believes that itself is fake and is creating the 'real' light. Both me and Zuranon thought it was fine to just do the refluffing as the element of [Light] is very compatible with Illusions in general.

Anyway, the usage of 'Subschool' in this is a vestige of that and is a wrong usage. You can't have a Conjuration spell with a Illusion subschool and etc.

In addition, in 3.pf there is no Light element, only the descriptor as yourself said it. You can't cause [Light] damage to people and there is no [Light] resistance like in the CYOA, those are things that Zuranon added. In general, zuranon uses the word 'Energy' to separate it from the descriptors and other 3.5 stuff.
The [Light] descriptor is probably separated from [Light] energy though they are related.

>[Shadow]
Now that is a victim of zuranon.
There is three types of [Shadow]
[Shadow] sub school of [Illusion]
[Shadow] descriptor, which tags spells that have to do with the Shadow plane
[Shadow] energy which is something that Zuranon added and is the advanced version of [Dark] and opposite of [Radiant].

>Morning Star
It didn't come up in the last thread but when I said 'Anti-Illusion' ability, I meant it as only anti-spells. This is like a SAC dispel magic targeted at a very few things.
Storyteller isn't a spell, it's a supernatural ability. my SAC ability do not affect it. Or at least that is the intention.
That is why it specifies 'spells' in it.
The only possible way that it could affect if is if Storyteller was a SLA, but it's not.

If in the NW spells and supernatural abilities are one and the same and it affects it or not is another business.