Complex sentence: The weapon that he conjures using his materialization abilities is a unique one--extending from his fingers of his right hand are five chains, which were specially created to deal vengeance upon the Genei Ryodan.
Split into simpler sentences: The weapon that he conjures using his materialization abilities is a unique one--extending from his fingers of his right hand are five chains. Some of the fingers were specially designed to deal vengeance upon the Genei Ryodan.