Ethereal Blade on Drow

Recently I had a match with Drow Ranger {http://www.dotabuff.com/matches/1382979902}. Because of some misunderstandings, we went for the 5 carry strat. After I got my Shadow Blade and Manta Style I decided to build a butterfly. Then after being zapped by Nyx Assassin a few times, I wanted to zap him back. Long story short, i decide to build an Ethereal Blade. Couldn't really finish it though so I do not know how well it would work. I mean as with the Morphling shotgun build, I could cast it and then purge the debuff by using Manta Style. So, would it work?

To use it offensively as a nuke? No, it's a complete waste of gold.

To use it defensively as a Ghost Scepter on yourself or your teammates, it can make sense in some games. But not when you're facing heavy magic damage like in this game.

I meant as a nuke and now that i think about it, it will be a waste of gold.

You could use Manta Style to purge the debuff but Nyx would stay in ghost form anyways which means you couldn't attack him. Actually, I think you help your opponent with that item in that case :)
In my opinion, Ethereal Blade is rejected item for Drow Ranger. Maybe could be used only situational.

you dont become ethereal if you use eblade anymore.