The Power Staff.

I think the Wonder Rod, Sage Staff, and Wizard Rod all have *abilities* that can be reflected (random chance when you hit something with them) but cannot be inherently reflected like the Power Staff, the most underrated weapon ever.

On a side note, I do consider the Bone Mail the best armor, because you can use black magic to heal. I never liked using white magic, anyway. But if it isn't that, the White/Black provide the highest magic defense, I think, and the Crystal Amor is the best physical defense.

Related to the last question:
What does the Power Staff do, that can be reflected?