This Batman, does he use a nailbat? I've pondered on making a flaming nailbat. I'd use an steel alloy bat and drill, cut, and weld things as needed. You'd want some kind of compressed gas since that should give an even burn and wouldn't leave your bat dripping with napalm or gasoline and that could drip onto you. You'd need some way to light it, so a stun gun wired and arching across the nails should do the trick. You could build the compressed gas canister storage inside the bat, but would probably be better to have the canister attached to you with a line running through a flexible metal conduit so it can't be easily cut or broken. If you're already running a line with fuel stored on you, then you might as well put a liquid line and tanks on your back for napalm or gas to shoot out the tip of the flaming electro nail bat. Maybe weld a triangular bayonet on the tip.