Depend on the helmet
when you use the cube recipe on an ethereal armor(which normally adds 50% def bonus), it then applies that 50% bonus again, on the total def instead of the base.
What this means is that if you have an armor with a normal def of 100, it would have 150 def as ethereal, and 225 def after ebugging. Now apply that formula to say a perfect sacred armor(600 def)(900eth), you now have an eth armor with a whooping 1350 base defense