If you've guys have tested it on the real server and confirmed that it ignores invincible / physical shield then SE changed it from the test server version. Most likely in response to the sheer negativity reported, hence that whole "does damage to resistant enemies" spiel that made on it.

In this case it would be useful for monsters that would otherwise resist other forms of damage. It being physical and having a -20% attack still renders it's damage pathetic on anything with decent defense. Possibly try it on that Flan VWNM as its highly resistant to physical damage.

And that comment is directed at all the people comparing a physical WS to known magic WS. And even going further and saying that because it has a SC property that it ~must~ therefor have an element.