wait wait wait make it so that he can use aany flame but he needs to train to be able to use it and he needs to have a picture or understanding of the flame no use trying to use a flame that you dont know or u dont understand how to use
how about some form of evolving Living flame like a spirit of sorts or something like the fiendfyre spell from HP where the more it devours the stronger it becomes usually taking the form of animals like fire snakes, wolves etc that keep spreading the flames
he can use flame like jet booster to boost punches and condence the fire. can you please make move like cruel sun it would probably only be used on nomu & and to scare the villains. you can also make him absorb fire rather than eating it like dragons Slayer in fairy tail (natsu).
