Twilight Archon was in fact a thing at one point. I recall the name as well. But I think that was a beta name and at some point down the line they just named it back to Archon as it was in StarCraft.
I made my own thematic ideas surrounding the StarCraft Archon with its Psionic naming and theme as it’s very similar to the Psychic and Mind/mental themes as well.
If your curious as to some ideas and gameplay changing mechanics I’ve come up with, see below…
Also I have a different direction that focuses more on the DPS side direction for Archon and by Contrast for Voidweaver in splitting the focus of your damage profile to be Non-Periodic for Archon and Periodic focused for Voidweaver.
In this post, I also include many ideas to improve the existing talent trees (class and Spec) for shadow.