Something doesn't add up regarding the connection between Amdapor and Norvrandt...

[ObsidianFire]

Umbral / Astral is a different axis than Light / Darkness

As of ShB, this isn't correct anymore. It would be more accurate to say that Umbral/Astral is the effect of the Light/Darkness cause.

Light and Darkness are like two poles of a magnet. Light pulls aether into a Static State and Darkness pulls aether into an Active State. On the Source, Umbral is associated with Static Aether, and is therefore caused by Light. Darkness is associated with Active Aether and is therefore caused by Darkness.

On the 1st Shard, Umbral and Astral aren't even terms people use to describe aether aspects. Instead they use Light and Dark to describe what causes aether to be in the state it is in.

I think it's wrong to say that Umbral and Astral are mislabeled when they were never really identified with Light and Darkness in the first place. They are terms that describe an effect Light and Darkness cause and the effect they are describing is something that does happen. It's just that the cause of Umbral and Astral aether was never named on the Source. Probably because the Source has never seen a time where Light and Dark have been universally out of balance to the degree that the 1st Shard did.