Complex sentence: Mephisto sends Vengeance to kidnap Roxanne Simpson to force Johnny to cooperate; as Ghost Rider, he chases down and defeats Vengeance and then returns to Earth.
Split into simpler sentences: Mephisto sends Vengeance to kidnap Roxanne Simpson to force Johnny to cooperate. As Ghost Rider, he chases down, defeats Vengeance, and then returns to Earth.