0_Eclipse_0
I don’t know if you already answered this question but will Blaze eat a devil? Obviously he will focus on his breathing techniques but maybe he can get a support type devil fruit. Like maybe he can get one with good regeneration or healing abilities so he can train harder and longer. Or maybe he could eat bird zoan so that he can fly to places without needing a boat like a mythical great roc or maybe a giant ancient bird.