Piercing

ON REPELLED: Destroy target and DISPEL

When you have it: One of the best offensive armors in the game, because it kill nearly ANY enemy regardless of their armor or orientation (but beware Guardian Angel). Even when you have armor on all sides, you might consider swapping one out for this.

When an enemy has it:

You can't let them hit you with it, or you die. Guardian Angel can save you if you let them hit a naked side.