What's the point with that quite lackluster story in Endwalker?

[DevonEllwood]

Azem mask is unknown at the moment when Emet-Selch glimpses Azem in us, he sees Azem without the mask, but the face appears blank to the player. Elidibus later also perceives the us as Azem, and in that vision Azem is wearing a black mask

Then I guess this mask is just a generic red mask? It's weird it's on a lot of the Hades weapons and prominently on his design and I could have swore the scene on the moon focused on it as well. I originally thought it was the "un angry" Hades mask, but in Elpis he uses the one on his chest. My initial confusion was because of the circles on the mask are pretty similar.