How do I go about making a new type of weapon??(dbz)

[Vaderbug71]

I have an idea that I think would be neat. Instead of the bryar pistol, what if it was hands, cupped in an outward blasting stance. Then when you fire the main trigger, you hear "Haaa" and a small beam of yellow light fires off, but if you hold down the 2ndary, (instead of a powering up like normal) you hear "Kaaaameeeehaaaaameeeeeeeee...." and then the pitch stays the same, but like the bryar pistol a ball of energy glows larger, but with this it almost fills your screen because it is a huge ball of energy with lightning sparks coming off of it, the you let go and you hear "Haaaaa" and it fires the blast, it would have a large blast radious and could use the rocket/emp pistol/bryar pistol 2ndary to make a neat blast on whoever it hit. Well I want to make this weapon mod, I can get the sound of the kamehameha wave. Please help me if you can, my email is vaderbug71@hotmail.com