Complex sentence: William's main rival, Hubert Lane is a stuck-up kid and a nasty piece of work, he too has a gang, where William's is called the outlaws, Hubert's is called the Hubertlanites.
Split into simpler sentences: William's main rival, Hubert Lane is a stuck-up kid and a nasty piece of work. He too has a gang, where William's is called the outlaws, Hubert's is called the Hubertlanites.