The Fire Demon is a minor antagonist in the DC universe. It appeas as a bit fighter in the Non-Disney vs. DC Villains War.
Non Disney Vs DC Villains War
Sealed within a forest, the Fire Demon is summoned by Rothbart, and his associates, Clavious and Zelda, as they break the borders, that imprisoned the demon in the first place. They then send him to rampage a forest nearby, unbestknown to him, that he was set up. The Fire Demon unleashes his all mighty power in the nearby forest, destroying a tree, that held Hexxus, ultimately releasing him. The Demon then attempts to weaken Hexxus with his fiery powers. However, Hexxus proves superior to the Demon, as he easily blows off his attacks, stuns him with his own powerful force, weakening him, and then absorbs his lifeforce, assuming a much more powerful form in the process, with the Demon's lifeforce living within him.