Complex sentence: Like PileVolcamon, the Mega form of his rival Volcamon, KingEtemon is a pro wrestler, using the gimic of Rock and Roll as opposed to Heavy Metal.
Split into simpler sentences: Like PileVolcamon, the Mega form of his rival Volcamon, KingEtemon is a pro wrestler. However, unlike PileVolcamon, KingEtemon is associated with Rock and Roll as opposed to Heavy Metal.