Emperium Aurora is for status. The status you gain from it is basically like the percentage that is script in other Auroras also. It just depends on the type of game play you build. Rune of Power or Zodiac for higher HP and a few more damages if you don't have any other demi-human stack item equipped. With Emperium Aurora, you can just wear on any class and build it to anything. For an example, if I was to play Champion. I wouldn't use Rune of Power or Zodiac Aurora. I'd build it with Emperium Aurora because Rune of Power have the 8% physical damage to demi-Human. There are already demi-human percentage damage from Dorcus, Goldenring, Fallen Bishop, etc. that I equipped. I'd just use the Emperium Aurora for build. Don't need too much stacks of demi-human. Status is recommended more for damage. You'd like some more physical damage than just towards demi-human. That is just an example why you should build a class with Emperium Aurora because you need status points more. Same goes with Rune of Power and Zodiac. There are classes that recommends HP more and these Auroras fit them. The other effects replace the 5 stats loss away from Emperium Aurora.
Emperium Aurora
All stats + 25. (If you need status more on what you're playing, use this. Stats toward physical damage. Not just towards certain type of property. Its to all)
Zodiac Aurora
All stats + 20, Physical Damage +5% Matk+5%, Vit Def -5%, Max HP +5%. ( Use this if you have enough stats and don't need Emperium Aurora. The +5% Physical Damage makes it up and does more. You'd like some -5% off vit defense which is good again Ice Pick or Thana. 5% HP is more than +5 towards vit depending if you have some vits or not.)
Rune of Power
All stats + 20, Increase damage by 10% and max HP + 8 ( If it was physical damage, I'd use this all day and it is better than Emperium in damage wise but no. It does more demi-human, don't need it. We need the +5 on str or dex or whatever your class requires for more physical damage. Use this for more HP though. 8% MAX HP is more than +5 towards vit. (referring to Emperium Aurora) You gain more from the percentage of your maximum HP. 8 % of it. )