To be fair, it's not like that weapon is locked to one part of it. Creative license.
And none of them are very extreme to start with.
Ether is by definition of Fate/, a kind of formless True-Neutral energy. It's actually the energy of thought.
In this case, the concept of water, applied to ether, turns it to water ether.
Kinda a double-state, Concept applies to all ether. So transformed things are the same except for being made of ether.
As for the weapon, Xenoblade. It's edge is made of ether, and turns what is before it formless, if only for an instant before it's overwritten. That instant however, is enough to effectively remove what it cuts, so a Lightsaber without heat would be a good analogy.
It's also tied to every one of those Monado Arts. As for your understanding of them, everything is correct.
Not surprisingly, More Ether around=Stronger effects. And Eat/Devour doesn't even work if the enemy hasn't been converted to ether by Break/Destroy.
Will send world PM tomorrow then.
"Thought to Law" When the area is completely overwritten by ether, I can change the natural state of things by overruling the Concept of Ether-materials. If it doesn't have a soul, it can be changed. Ether=Thought
This takes a long long time though, so it's not immediately ready. Just something more to do with being a demi-goddess.
For all that skill is corruption, all it does is change things to an ether state.
Ether Zone is also the right description. Hopefully I survive long enough to reach a portion of my old strength.