Complex sentence: JB breaks free and destroys Spiderbot; first he stabs it through the stomach with the Laser Lance, giving it'heartburn', then cures the'heartburn' by finishing it off.
Split into simpler sentences: JB breaks free and destroys Spiderbot, first he stabs it through the stomach with the Laser Lance, giving it'heartburn.' JB cures the'heartburn' by finishing it off.