Implemented! Thanks for all the comments and congratulations!
Degen Aura got no aura graphics atm. Obviously, that sucks.
I had a bunch of ideas, all with complicated runes forming an aura and stuff (the Textures\Rune1d.blp texture has been suggested often for example), but I thought for an aura with such a small AoE we shouldn't have have an intricate rune but rather something subtle.
So if I got that right degen comes from degeneration, and the easiest way to display that would be to make it look like Omniknight drains the energy from units around him.
Sadly, it is difficult to show this kind of emitter in a screenshot.
Here's the best one I made:
I highly recommend checking the testmap to know how it looks, the screenshot is not representative at all.
If you don't want to check it, but are experienced with modeling:
It is a particle emitter using Textures\ShockwaveWater1.blp tinted white-yellow/yellow/white-yellow (roughly 0.5/1/1->0/1/1->0.5/1/1 B/G/R), scaling from 200 to 75 with -50 gravitation.
The MSI is 314 byte, that's about 1/50 of an icon for an item.
I'd be glad for any kind of feedback as long as it is constructive.