Complex sentence: Batman breaks into LexCorp and steals the kryptonite, in preparation to battle Superman by building a powerful exoskeleton and creating a kryptonite-powered riot gun and a kryptonite-tipped spear.
Split into simpler sentences: Batman breaks into LexCorp and steals the kryptonite. He prepares to battle Superman by building a powerful exoskeleton and creating a kryptonite-powered riot gun and a kryptonite-tipped spear.