Activate the munitionfrenzy code. On the left and right of the Wave Motion Cannon, there will be one small dot on each side. One has a WMC logo that does not work and the other has a Mercury Bow logo. Get the Mercury Bow dot. Fire, and it will be the same weapon that Mukade uses. Note: This is almost like the Screaming Cannon; it will hit you if there are no other targets.