Jack Vance 
Book of Dreams [EPUB ebook] 

Kirth Gersen carries in his pocket a slip of paper with a list of five names written upon it — the names of five Demon Princes. The Demon Princes are a race of beings who disguise themselves as humans and delight in power and destruction. However, to Kirth they are merely murderers who killed his family and destroyed his home planet — and who deserve to die for those misdeeds. Three have already fallen at Kirth’s hands, but there are two more names on the list.