Luffy himself did more damage to him than anyone else in the whole one piece world bar Akainu. Child Luffy is stronger than Arlomg, Lucci, Crocodile, Kaidou, Katakuri, Doflamingo, Mihawk, Aokiji, Kizaru, Pacifista, Moria etc. None of them was able to scar Luffy like child Luffy did to himself...