I wasn't really going to say anything about this. 

Essentially, Ether/Mana/MP/Spirit/Ki/Chi/Aura/Ckakra/etc. are all the same thing, just go by different names. They are all labels used to identify spiritual/magical energy which is typically regarded as a fuel for a wide range of powers unless the writer specifically denotes an actual difference. But said "different" energy would be what Mobius is referring to as "Realm Energies" which implies its a form of energy which someone is regarding as unique to their own stories. 

And that is basically the problem with said Realm Energies, because people can usually pick and choose what can or cannot effect it, because its unique for them and them alone. (Not saying I'm against folks using their own creative ideas of energy, just trying to keep things in perspective is all) As opposed to the concept of Ether which is being applied as a broad term to refer to Magical/Spiritual Energy in general.

The REAL differences are how people USE Ether for their characters. Some folks will use Magic that actually draws upon their internal reserves of energy or merely draw upon the energy around them. Others will likewise employ different mechanics. In terms of magic, this is usually embodied in the VAST variety of different schools; Necromancy, Conjuration, Destruction, so on and so forth. And even then, there are likewise even MORE variations of each individual school. 

But at the end of the day, it always boils back down to the unifying concept that Magic is Magic is Magic.

Fantasy is broken down into Magic or Spirits.
Sci-Fi is simply Tech. But Tech can also cover a huuuuuuuuuuuge category. And in many respects, Tech and Magic can coincide with one another. For example, Mass Effect "Biotics" is more deemed as Tech in this sense because its more biological in nature.

Its all about what you're using and how you're using it.