Complex sentence: During their battles with each other, a Great Unseen Voice projected down from the sky and told them they were to be best friends, sent through time to the 21st century, where they were given a mission.
Split into simpler sentences: During their battles with each other, a Great Unseen Voice projected down from the sky and told them they were to be best friends. Sent through time to the 21st Century, where they were given a mission.