Etheral Units... but not.

[sabatadark]

I want these units I'm making to be etheral, but be attacked as normal and can attack as normal. Being etheral doesn't allow this.

 

[Napenthe]

So, you just want to make a unit that takes extra damage from spells or you just want the ethereal visual effect on the units?
Looks to me like you have to make a copy of the ethereal form ability and an ethereal forms version of the unit that's going to be using the ability.
Change the 'Data-alternate form unit' line in the ability to the ethereal unit version, give the units the apropriate abilities... and i think that would do it.

Or just change the combat stats of the spirit walker (ethereal) unit.