I wanted to give Killbison his cannons, so tore apart an Energon Brawl and modded the turret.
It plugs into an existing socket on the turret, which was ideal for me because it meant no changes to the base figure. And it can rotate!
It looks a bit bulky when in Leokaiser mode, but luckily it can be plugged into the back of my custom Leozack.