Complex sentence: Eventually, Superman gets the upper hand and subdues Zod, but the General prepares to murder a trapped family with his heat vision and claims he will never stop, forcing Superman to reluctantly snap Zod's neck to save the family, killing him.
Split into simpler sentences: Eventually, Superman gets the upper hand and subdues Zod, but the General prepares to murder a trapped family with his heat vision and claims he will never stop. Morally torn, Superman is forced to snap Zod's neck to save the family, killing him.