The Killing Machine (Demon Princes, #2)

Having brought arch-villain Malagate the Woe to justice, Gersen now sets his sights on Kokor Hekkus, another of the Demon Princes. The name Kokor Hekkus, which means "killing machine" in the language of the planet Thamber, does not refer to Hekkus's own predilection for homicide, but to his fondness for horrific and murderous devices, including the giant robotic executioner that first gained him his nickname.

The Killing Machine is part 2 of 5 of The Demon Princes Series.
The Demon Princes is a five-book series of science fiction novels by Jack Vance, which cumulatively relate the story of one Kirth Gersen as he exacts his revenge on five notorious criminals, collectively known as the Demon Princes, who carried his village off into slavery during his childhood. Each novel deals with his pursuit of one of the five Princes.