Separately, the Black Sword and Bright Shield are not True Runes, but together they make the True Rune called the Rune of Beginning. I also believe that this is discussed on this board somewhere else.
I believe it's actually here in about five places, at the moment, both in its own topic as well as other related topics because it keeps coming back to haunt us.
I believe the reason it says one of the true Runes for Riou's Bright shield rune may simply be the fact its part of the rune of beginning in that its at least an aspect. Even though its not a True Rune in itself its probably still seen as one due to the fact the shield rune from three was most likely born of it.
There was a Shield Rune in 3. Aila has one equipped to her from the very beginning. It's hard to say whether or not the Shield Rune came from the Bright Shield or not, but it does seem rather likely. The fact is that the Bright Shield is not a True Rune, it is a component of a True Rune. The Rune of Beginning is the True Rune, not the Bright Shield or Black Sword Runes.
why does it say that Bright Shield and Black Sword are True Runes on their own? I was told they weren't true runes at all...yet it says in the game 1 of the 27 True Runes for both Bright Shield and Black Sword.
What's in a name? There are things that are best kept secret with this type of mission.