Complex sentence: Batman and Superman fly off to Tokyo to submit the meteor's data to the Japanese Toyman, who has already built a giant rocket-propelled spacecraft, intending to use it a large missile to stop the meteor.
Split into simpler sentences: Batman and Superman fly off to Tokyo to submit the meteor's data to the Japanese Toyman. The Japanese Toyman has built a rocket-propelled spacecraft, intending to use it as a powerful missile to stop the meteor.