Really, Chaos isn't so different from a Harmonixer when you think about it. He is a being forged by the will of the four fiends and commands all of their powers in battle. Rather like the way Kurando uses Jutendouji and Tsukiyomi, Chaos commands his own demons. Thus this isn't a battle of pure combat - though Chaos could win that handily with Cure 4 and patience - but a batter of master against master in the arena. So look at Chaos! He commands the four primal elements of nature! What does Kurando command? A moon spirit and some sort of loincloth clad ruffian from an old story? It hardly compares, and it's not too hard as a result to figure out why Chaos obliterates Kurando.