I was so certain that this effect was glitched and was going to get patched that I wasn't going to respond to this thread. Now, several hotfixes later, with no response and a "working as intended" I gotta chime in. This is without a doubt the most annoying animation in the game for me to date. Holy spam? Taken care of with filters. MNK/WAR auras? Nowhere near as invasive or persistent. Darkside aura just looks broken and terrible to me, and I really hate that I have no way of getting rid of it.
In combat, it's fine. No big deal at all. In town? With a half dozen other glowing DRK nearby? Ugh.
The worst is when I go to take a screenshot of a non CS npc saying something funny or I want a group shot with npc celebs out and about, only to have the entire scene distorted by the wavy red aura of idiocy emanating from a dark knight that isn't even on my screen. Working as intended? You gotta be kiddin' me.