Complex sentence: However, the Great Shutdown meant his plans could go no further-until Unicron's servant Scourge located Cybertron and reactivated him for study, but when Shockwave was attacked by Sharkticons Scourge saved him, only to be shot in the back by Shockwave.
Split into simpler sentences: However, the Great Shutdown meant his plans could go no further--until Unicron's servant Scourge located Cybertron and reactivated Shockwave for study. When Shockwave was attacked by Sharkticons Scourge saved his life, only to be shot in the back by Shockwave.