Have you ever read a novel where the main character uses extraordinary fire to fight?

I think "Full-time Mage's Undying Fire" might meet your needs ~ The protagonist of this novel, Lin Ran, was born with the Undying Fire. When he was injured, the flames on his body could help him quickly heal himself. He used flames to fight in the Otherworld, and this kind of flame was very special! I hope my recommendation suits your taste. If you like it, remember to tell me~