User blog comment:Pandawarrior/Logia vs. Logia/@comment-125.60.236.110-20110325075044/@comment-1949750-20110325081619

not sure about that but my theory is that magma is just too hot for ace since magma is much hotter than fire. A sudden massive difference in temperature between two objects contacting each other will cause a burn. like how person will feel more heat if they touch hot water when their hand is cold than a person touching hot water with their warm hand.