It's not an aura, those are separate costume pieces called Ascension Radiance, and you can only get them from the Empyrean vendor (not sure why you're not seeing them, are you sure you're at Michael and not Christy?).
"You don't lose levels. You don't have equipment to wear out, repair, or lose, or that anyone can steal from you. About the only thing lighter than debt they could do is have an NPC walk by, point and laugh before you can go to the hospital or base." -Memphis_Bill
We will honor the past, and fight to the last, it will be a good way to die...
Check your filter to make sure you don't have it hidden.
"Mastermind Pets operate...differently, and aren't as easily fixed. Especially the Bruiser. I want to take him out behind the woodshed and pull an "old yeller" on him at times." - Castle
I really like one Ascension aura I have seen in game. It perfectly matches the countour of the Ascension shoulders, but I cannot find it at the Emp vendor. Anybody know where to get this/unlock it?