A beam katana was a lame imitation lightsaber weapon that was used by certain primitive societies that still thought motorcycles were awesome. Although a step up from bladed melee weapons, it couldn't stand up against real lightsabers in battle, and it also shorted out when it touched water... like in the rain, for example, or when somebody pulled the fire alarm and turned on the sprinkler system. The most crippling deficiency of the beam katana was that it required a Wiimote to operate.