Ghost Blade

A sword, or more realistically a sharpened rod. The blade can become selectively incorporeal anywhere along the length, allowing it to bypass armor or physical objects with proper usage. The downside is that the edge and point of the blade are totally normal and the damage it does relies on the force the user can exert. 
Ammo: Recharging internal system. Can run out of power if used many times in a short period, but for the most part is infinite. The longer the blade is kept incorporeal, and the greater the length of the incorporeal section, the greater the drain.