As far as I know, the light doesn't change much besides the powers and the ability to be rezzed.

However, I remember it being said that Guardians don't get sick and don't scar. And I'm not sure if the memory wipe after being chosen has anything to do with it.

And there's also the case of the Hive's Light Brood. What changed with them?

There is something I have been never thought of until recently. How "common" are some of the exotic weapons and armor pieces? I know that many of them, like the Wish Ender bow for example, they should only be a one-of-a-kind, since there was only one Sjur Eido in existence, but for something like the Thunderlord, I'm sure it would be stupidly expensive resource wise to make, but it would be possible to make more of them, and for the Chaperone and The Last Word, easier, but still expensive. And for armor, I would imagine something like The Helm of Saint-14, there would only be two as there was the one that was found after he disappeared, and the man himself. And for Young Ahamkara's Spine, those would be rare to find among Hunters as the Ahamkara are extinct. So again, what would be the commonality-to-rarity ratio of some of these weapons?

I’ve looked at a few sites and I’m unsure where to find a good copy (and a reliable site) to buy the 7th grimoire in the series. Does anyone have any recommendations?