Hahaha, you mean scattershot right? Its really easy how it works, lemme explain quickly. Select the weapon up and charge a shot. After you fire it it comes out as one big ball, but if enemies are in the area, the ball will split up automatically and send smaller balls at each enemy character. Really simple, no kamehameha torpedo, just charge up a shot and fire, the game does the rest for you.
One quick note for you, the ball wont split up if there are no enemies present