Powers:

Flight: Firefly has a set of wings that allow him to fly.

Napalm: Firefly carries a gun connected to canisters on his belt that allows him to project jets of Napalm.

Body Armour: Firefly wears a suit of armour that offers a degree of protection against heat and flames. The helmet helps protect him from smoke inhalation.

Resistance to Pain: Firefly’s nerve endings are overloaded which means that he won’t feel the pain from an injury for hours.

Origins:

Garfield Lynns used to work in movies as an expert in pyrotechnics. His occupation hid his real obsession, Pyromania. Being Hollywood’s master of explosion and fire effects wasn’t enough for him. He turned to arson for profit and then arson for pleasure.

Notes:

Firefly at Batman Wiki

Firefly at DC Database

Firefly at Comic Vine