one piece spoilers below, although it's fairly well known what im talking about
I believe that should Ace have survived the war of the best and was allowed to train like luffy was allowed to he could put some spins on his DF like luffy, like being able to spontaneously jump to fires (Got that idea from what embers do) and cause a fire on the spot, by that I mean not having to be in physical contact to cause fire, If you follow.
And if Ace was to gain proper control of Haki like luffy did, I would dare say it would be stronger than his, as Ace showed the Conquerors Haki as early as 10 years old, while luffy first demonstrated it somewhere between 17-18 years old and while that might not neccessarily mean anything I think it's a good hint at where they're at when compared to eachother
And if Ace was to gain proper control of Haki like luffy did, I would dare say it would be stronger than his, as Ace showed the Conquerors Haki as early as 10 years old, while luffy first demonstrated it somewhere between 17-18 years old and while that might not neccessarily mean anything I think it's a good hint at where they're at when compared to eachother