The Ion Gun is a weapon appearing in Custom Robo (GameCube). It fires a shot which stops and re-aims several times. Though not a very powerful gun, it can be quite formidable in the hands of a skilled commander. It is fairly easy to use.
This gun fires two rounds--which then reacquire the target's position twice before launching at them. This allows you to place more rounds in different locations on the field before they move. Use your bombs and pods to force your foe into the line of fire. The Ion Gun is best-used for short- to mid-range combat.
This gun can be very annoying to amateur players, as its homing capabilities and stunning shots are a real nuisance. To avoid it, do everything you can to keep under cover by hiding behind walls. Then you have to slightly tap the jump button to do a small jump, then fire your gun or bomb. For guns, the Sniper and Dragon Gun do fairly well against opponents with this weapon.